Method and apparatus for determining the location of an occupant of a vehicle

ABSTRACT

A method and apparatus for use in locating the eyes of a vehicle driver or passenger in a vehicle for controlling vehicle systems including the positioning of vehicle sideview mirrors in relation to the driver&#39;s eyes to maximize the view of traffic on either side of the vehicle or the characteristics of vehicle airbag deployment. The location of a driver&#39;s or passenger&#39;s eyes is derived from the adjustment by the driver (or passenger, if capable of doing so) of adjustable light beam(s) emanating from light source(s) or illuminated indicia, until it (or they) intersect the driver&#39;s or passenger&#39;s eyes. From the angles of adjustment of the light beam(s) and other known coordinates of the vehicle, the location of the driver&#39;s or passenger&#39;s eyes or the target may be computationally derived as a set of Cartesian coordinates. The determined eye location of the driver may be used together with the known mounting locations of the driver&#39;s and passenger&#39;s sideview mirror assemblies to derive exterior sideview mirror pitch and azimuth adjustment signal sets correlated to the vehicle blind spots. The adjustment signals are applied to servo motors operating in a feedback control loop to correct the actual driver&#39;s side and passenger&#39;s side sideview mirror pitch and azimuth settings to properly reflect images of the driver&#39;s side and passenger&#39;side vehicle blind spots to the driver&#39;s eyes. The determined eye locations of the driver and passenger may be also or alternatively employed in the control of the airbag deployment system and in other vehicle safety and comfort systems. The relative fore-aft distance away from the airbag and the height of the person or target can be computed, and airbag deployment force and/or duration adjusted to compensate for deviation from the standard height and fore-aft distance.

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/379,272, filed Aug. 23, 1999, now U.S. Pat. No. 6,176,587issued Jan. 23, 2001, which is a continuation of U.S. patent applicationSer. No. 08/818,628, filed Mar. 14, 1997, now U.S. Pat. No. 5,993,015,filed Nov. 30, 1999, which is a continuation-in-part of U.S. patentapplication Ser. No. 08/374,220, filed Jan. 18, 1995, now U.S. Pat. No.5,668,675, issued Sep. 16, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for use inlocating the eyes of a vehicle driver or passenger for controllingvehicle systems including the positioning of vehicle sideview mirrors inrelation to the driver's eyes to maximize the view of traffic on eitherside of the vehicle and the characteristics of vehicle airbagdeployment.

2. Description of the Background Art

Passenger and commercial vehicles, e.g. automobiles and light trucks,are typically provided with a number of comfort features for the benefitof occupants and safety features and systems that are intended to helpavoid collisions or to ameliorate the effects of collisions. At thistime, virtually all enclosed vehicles, i.e. automobiles, sport utilityvehicles, vans, trucks, etc., are provided with safety belts for use byoccupants to strap themselves in. In addition, at least front seatdriver's side and passenger's side explosively inflated airbags havebecome standard equipment in such vehicles. Typically, airbags aremounted in the steering wheel hub and in the dash area forward of thefront seat passenger and, in some cases, in the vehicle side doors. Theairbags are inflated when sudden deceleration of the vehicle is sensed.A force and duration of deployment is currently prescribed that isstandardized to average driver and passenger size and seat adjustmentposition.

Moreover, vehicle mirror assemblies and adjustment systems are providedas standard safety systems in such vehicles. An interior rearview mirrorfor viewing rearward of the vehicle and exterior left (driver's side)and right (passenger's side) sideview mirrors with which the vehicledriver can view traffic to the sides and rear of the vehicle withincertain fields of view dictated by the positioning of the mirrors areprovided as standard equipment. Typically, the interior rearview mirrorcan be manually adjusted about horizontal (pitch) and vertical (azimuth)axes through its mount to the headliner or windshield to providecorresponding pitch and azimuth angle adjustment of the view through thevehicle rear window. Even when properly adjusted, the borderingstructure of the rear window limits the view to either side.Consequently, vehicles are provided with left and right exteriorrearview or sideview mirrors that are typically mounted at the juncturesof the left and right windshield pillars with the adjacent front seatside windows. Mechanical or electro-mechanical, remote joystick controlsare provided to allow the driver to adjust the sideview mirrors forazimuth (side to side about a vertical axis) and pitch (up and downabout a horizontal axis perpendicular to the longitudinal axis of thevehicle). Improper adjustment of the sideview mirrors, particularly inazimuth angle results in wide “blind zones” or “blind spots” on eitherside of the vehicle.

Such blind zones or spots are widely described in the prior art, andexamples are depicted as shown, for example, in the FIGS. 1 and 4 ofU.S. Pat. No. 5,033,835. The blind zones on either side generallysubtend an azimuth arc angle between the limits of the driver'speripheral vision while looking ahead and the left and right limits ofthe fields of view of the left and right sideview mirrors when themirrors are aimed along the vehicle sides and a pitch angle generallybisected by the horizon. The blind zones are really cone-shaped tunnelareas expanding outward from the sides of the vehicle slightly downwardfrom the eye level of the driver and away from the vehicle sides.Customarily, these right and left blind zones are referred to as blindspots, and that term will be used hereafter.

The current method of exterior sideview mirror alignment used onvirtually all domestic and imported passenger vehicles simply relies onthe driver's judgment as to the proper imagery he/she should seereflected by the sideview mirror. This is supposedly gained byexperience with different settings. Many drivers erroneously believethat correct azimuth angle alignment is achieved when the side panels oftheir own vehicle are reflected back to them along one edge of theexterior sideview mirrors when they are in their normal drivingposition.

A wide number of solutions to the problem of correctly setting thesideview mirror position to maximize the view of the blind spot havebeen proposed but not adopted. One approach is to attempt to enlarge theviewing angle. Wide viewing angle, static mounted, sideview mirrors anddynamically movable sideview mirrors are the subjects of U.S. Pat. Nos.4,019,812, 4,187,001, 4,318,590, 4,439,813, 4,575,202, 4,792,220 and4,971,930. All of these proposed solutions require either bulkyassemblies, distort the image in the field of view so that the driverdoes not see all the potential safety hazards in correct prospective, orare complex electro-mechanical systems with intermittent or continuouslyrunning motors and subsequent noise and vehicle power drain.

Further approaches to solving the problem of correctly aligning thesideview mirrors to eliminate or minimize blind spots are set forth inU.S., Pat. Nos. 5,022,747, 5,033,835, 5,122,910 and 5,237,458. The '747,'835 and '910 patents employ an auxiliary mirror built into a corner ofthe sideview mirror which images a reference point or marker on thevehicle side to which the mirror is mounted when the main mirror isproperly aligned to image the vehicle blind spot. In another form of the'835 patent, the sideview mirror is first adjusted by the driver toimage the reference point, and then the electro-mechanical systemchanges the alignment a preset amount to image the blind spot. A lamp onthe adjustment mechanism lights when the final alignment position isachieved by the system.

The use of auxiliary mirrors on or visible through the front surface ofthe main sideview mirror that are large enough to view a vehiclereference point reduces the mirror surface area for viewing into theblind spot. Also, the imaged target on the side of the vehicle may notalways be clearly visible due to road grime on the vehicle or simplybecause of low ambient lighting. Finally, salient auxiliary mirrors andtargets on the side of the vehicle large enough to be seen by the driverare anathema to automotive stylists.

Moreover, such approaches provide only a limited range of correct mirroradjustment and are not usable in all seat positions for all driverheights. In this regard, it should be noted that the '747 and '910patents profess that their disclosed systems are insensitive to driverheight and seat position of up to 8 inches fore and aft and up and downfrom a “standard driver”. However, the illustrations of FIGS. 8 and 9confirm that the rearward views attained at these nonstandard positionsdo widely vary and are not ideal. The ability of the non-standard driverto rely on the setting attained by imaging the vehicle targets dependsgreatly on how large the sideview mirror surface is. As vehiclemanufacturers seek to minimize sideview mirror size for styling andeconomy reasons, it is clear that this approach may well mislead driversof non-standard height or seat position preference.

The '458 patent professes to be an improvement on the earlier system ofthe '747 and '910 patents and discloses a light source 9 in the mirrorhousing 3 that illuminates a target 7 or is an illuminated target. Thetarget 7 is reflected by an auxiliary mirror 6 and through a lighttransmissive portion 5 of the sideview mirror 4. It would appear thatthe targeting approach taken in this system is geared toward ensuringthat an exact correct alignment is attained for a “standard driver”, andall other driver positions are only approximately correct. Again, theadequacy of the sideview mirror setting for non-standard driver eyelocations is highly dependent on the amount of the sideview mirrorsurface area.

In a further approach, certain automobiles have auxiliary turn signalindicators mounted above the front wheel wells to alert the oncomingdriver in the blind spot to the intention of the blinded driver to makea turn or lane change into that lane. It is also proposed to mount theauxiliary turn signal lights to the sideview mirror structure asdisclosed, for example, in U.S. Pat. Nos. 4,906,085, 5,014,167 and5,207,492 Unfortunately these forward mounted, auxiliary turn signallights may alert an overtaking driver in the adjacent lane too late tobe totally effective, and may even encourage drivers to fail to properlyset their sideview mirror azimuth angles or to even use their sideviewmirrors before initiating a lane change. In the latter case, carelessdrivers frequently change lanes without using their turn signals orsideview mirrors. Finally, due to their fields of view, if sideviewmirrors having such auxiliary turn signals are not properly adjusted inthe first place, the auxiliary turn signals may not be seen by anovertaking vehicle in time to react.

Turning to a further aspect of sideview mirror adjustment, frequently,two or more individuals may drive the same vehicle and each adjust therearview and sideview mirrors to their own liking. To avoid theinconvenience of each driver in having to readjust the rearview andsideview mirrors, it has been proposed that mirror settings be memorizedfor re-use when a specific driver identification code is entered. Theadjustments that are typically made by different drivers are mirrorpitch about the horizontal axis depending on the driver's height or boththe mirror pitch and azimuth, if the driver changes the seat height ordistance from the steering wheel. In certain vehicles having memorizeddriver seat positions, the mirror pitch and azimuth adjustment anglesare memorized with the seat positions as shown, for example, in U.S.Pat. Nos. 4,267,494, 4,625,329 and 4,727,302. Such systems do notnecessarily provide the optimum mirror adjustments for eliminating blindspots, but instead rely on the drivers to make the initial settings thatare then memorized.

Many vehicle accidents could be prevented with a simple opto-electronicmirror adjustment aid for left and right sideview mirror alignments toembrace the blind spots peculiar to each vehicle model in the reflectedimages seen by the driver. To be adapted by vehicle manufacturers, suchan aid must be inexpensive, reliable, consume minimal power, and be ableto be incorporated with new or existing mirror housings subject towhatever styling considerations are imposed. To be accepted by thedriving public, the aid must be simple to operate and must inherentlycompensate, at least approximately, for variations in driver height andseat position. This inherent compensation should be automatic and occuras the vehicle operator uses the aid's optical cues during mirroralignment. Moreover, when used, the aid should provide positive feedbackto the driver that assures him/her that the alignment is correct, evenif it appears to the driver to be incorrect. These goals are all metwith the embodiments of the present invention described in detailhereafter.

Returning to the use of explosively inflatable airbags, the deploymentof the airbags is beneficial or not harmful in the majority of cases.However, injuries to or death of small stature adults, children andinfants have been attributed to the airbag deployment force. The forceand duration of deployment is standardized to protect an average sizedadult located at an average distance from the airbag. If the person issmaller in size and closer than the average distance, the force andduration can be excessive and cause injury or death. In the case ofinjuries to or deaths of infants, many are caused by failure to use orto properly attach an infant seat to the front passenger's seat belts.Moreover, while the airbag force and duration is standardized to aparticular distance, the combination of the seat adjustment and the formor shape of the infant's seat may place the infant in jeopardy. This hasled to efforts to educate the driving public to locate infants andchildren in rear seats which many parents find unacceptable orinconvenient. Despite the clear evidence that airbags and seat beltscombine to save many lives, some are urging that they be allowed tooptionally disable the airbag deployment system. Rather than such anextreme solution, it would be more desirable to modulate the force andduration of the deployment to take into account the size and location ofthe driver and front seat passenger or infant's seat.

Many of the considerations to be taken into account and a system blockdiagram for making the deployment decision and controlling thedeployment force and duration or rate of deployment of single stage ormulti-stage airbags are set forth in the article entitled “Restraintsystem electronics”, Automotive Engineering August, 1996, pp. 27-31,incorporated herein by reference. In this article, a variety of sensorsare described for attempting to determine the position of the driver,passenger(s) and infant seat and other vehicle characteristics, e.g.vehicle speed and the like, that provide signals that are proposed to becombined to control the deployment of airbag(s). Unfortunately, many ofthese sensors, e.g., seat position sensors, seat belt attachmentsensors, weight on the seat measuring sensors are ambivalent orimprecise and can be fooled. Difficulties encountered with attempted useof a variety of sensors to locate a person in a front driver's orpassenger's seat are set forth in the article “What's a smart airbag'sreal IQ”, Automotive News, Feb. 24, 1997, p.1.

One further methodology for determining the location of a vehicleoccupant employing optical rangefinding techniques is described in thearticle by W. Chapelle entitled

“Sensing Automobile Occupant Position with Optical Triangulation”,SENSORS, December 1995, p. 18+, incorporated herein by reference. Thissystem requires use of a light projector, imaging lenses and photosensorarrays that are similar to those used in photographic cameras with aprojection light source. In such systems, it is difficult for the systemto determine just what aspect of the driver, passenger of other objectis being imaged. Again, such systems can be fooled by imaging on thewrong feature.

The above-described patents do not determine the location of the eyes ofa driver or passenger. Further U.S. Pat. Nos. 4,797,824 and 4,843,892 doseek to determine the eye positon of a driver. The '824 patent isdirected to a system for locating the driver's eye height in order tocontrol the automatic adjustment of the height of a seat head rest. Ahorizonatal array of differently colored light sources provide acorresponding vertically stacked array of light beams that are spreadhorizonatally so that the driver can see one of the fight beam colorswith both eyes. The driver indicates which of the light beam colors ismost intensely visible, and the coordinates of that light beam are usedwith the fore-aft seat and seat back angle position information todetermine the driver's eye height or “Y” component of the X, Y, ZCartesian coordinates of the driver's eyes. In this case, it is notnecessary and no means are provided to determine the “X” and “Z”components.

The '892 patent discloses an eye position detection system foradjustment of vehicle mirrors that relies upon the driver aligning asight marking on the interior rearview mirror with a sight marking onthe vehicle rear window and pickoffs for detecting the pitch and azimuthadjustment angles of the rearview mirror. When the driver indicates thatthe alignment is achieved, the driver's eye position is determined usingthe fore-aft seat plane and rearview mirror Cartesian coordinates,assuming the the driver is centered in the fore-aft seat plane. Thisapproach cannot be used in dim light or at night.

Moreover, most people tend to favor one eye over the other eye whensighting or aligning images and objects. This can lead to an error inazimuth determination of the hypothetical “X” coordinate component,which is ideally the center-point between the right and left eyes.

A more accurate and less ambivalent system for determining the X, Y, ZCartesian coordinates of the centerpoint of the eyes of a driver orpassenger in a vehicle seat is needed for the adjustment of the vehiclesideview mirrors and other vehicle components and systems.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for locating adriver's eyes or a passenger's eyes to allow for the automaticadjustment of vehicle systems to their eye locations.

The methods and systems or the present invention derive the location ofa driver's or passenger's eyes from the adjustment by the driver (orpassenger, if capable of doing so) of a light beam pair comprising righteye and left eye light beams. The directions of the right and left lightbeams are adjustable in tandem by the driver, the adjustments in pitchand azimuth about pitch and azimuth light beam adjustment axes havingknown Cartesian coordinates. The driver or passenger adjusts the lefteye beam and a right eye beam in tandem until they impinge upon therespective left eye and right eye with perceived maximal equalintensity. The right and left eye beams may be of the same or differingcolors.

In certain embodiments, the right eye beam and left eye beam are emittedfrom a common light beam housing, particularly from respective right andleft light beam emitting locations that are offset in the horizontal,azimuth, direction (or X coordinate) from one another and from thecommon adjustment axes of the light beam pair. The right and left eyelight beams are nominally directed in the same direction but divergeapart slightly in the azimuth direction. The angular adjustment of thelight beam housing is detected, and the location of the driver's orpassenger's eyes is computationally derived as a set of Cartesiancoordinates from the tandem adjustment of the binocular light beams andother known Cartesian coordinates of the vehicle.

Assuming a single light source housing for the moment, the pitch andazimuth adjustment angles of the housing are measured when the driver orpassenger indicates that he or she perceives the right and left eyelight beams to be equal and maximal in intensity. Pitch and azimuthangle adjustment measurement means, e.g., miniature angle resolvers or“pickoffs” are associated with the housing to measure the pitch and/orazimuth angles of adjustment of the light beams. The location of thedriver's or passenger's eyes is determined using triangulationtechniques employing the measured angles and the known Cartesiancoordinates of pitch and azimuth axes of adjustment of the adjustablelight beam housing and the known fore-aft seat adjustment plane for therespective driver's or passenger's front seat. This approach assumesthat the driver or passenger is centered in the driver's or frontpassenger's seat and therefor is centered in the fore-aft seat plane.

To provide a somewhat more accurate location of the respective eyes, atleast two light housings are employed, each emitting right and left eyelight beams. The direction of the light beams is adjusted using either apitch and azimuth adjustable light mount or an adjustable light beamreflector intersecting a fixed direction light beam from a fixed lightsource. The angles of adjustment in pitch and azimuth of both lightbeams are measured when both light beam pairs are adjusted to be seen bythe eyes. The location of the driver's or passenger's eyes is determinedfrom both sets of measured pitch and azimuth angles and the knownCartesian coordinates of the light beam pitch and azimuth axes,employing triangulation techniques.

The present invention may be embodied in other embodiments where thelight beam pair housing is not itself adjustable, and the right and lefteye light beams are reflected from an auxiliary mirror or reflectorassociated with the interior rearview mirror or one or both of thesideview mirrors. The combined mirror and reflector is adjustable inpitch and/or azimuth about respective pitch and/or azimuth adjustmentaxes by the driver until the light beams are visible to the driver's orpassenger's eyes. Pitch and azimuth angle adjustment measurementpickoffs are associated with the mirror to measure the pitch and/orazimuth angles of adjustment of the reflector. The eye locationintermediate the right and left eye is derived from the measured anglesof adjustment. Then, the sideview mirror pitch and azimuth adjustmentsignal sets and/or airbag deployment control signals are derived andemployed as summarized above.

The determined driver's eye location can be used together with the knownpitch and azimuth axes of adjustment of the driver's and passenger'ssideview mirror assemblies and known Cartesian coordinates of thevehicle blind spots to derive exterior sideview mirror pitch and azimuthadjustment signal sets. The adjustment signals are applied to feedbackservo motors operating in a feedback control loop to correct thedriver's side and passenger's side sideview mirror pitch and azimuthsettings to properly reflect images of the driver's side and passenger'sside vehicle blind spots to the driver's eyes.

The determined eye locations of the driver and passenger may be also oralternatively employed in the control of the airbag deployment system.The relative fore-aft distance away from the airbag and the height ofthe person can be computed, and airbag deployment force and/or durationadjusted to compensate for deviation from the standard height andfore-aft distance.

The determination of the location of the driver's and passenger's eyesalso allows a number of vehicle safety and comfort systems to beadvantageously optimized, including climate control, seat level, radiosettings, other mirrors, etc.

The eye location aids of the present invention may advantageously beemployed with both vehicle sideview mirrors and coordinated with thesetting of the interior rearview mirror in a variety of combinations andpermutations. The additional components of the mirror assembly (if any,in the particular combination) are relatively inexpensive and durable.In the disclosed embodiments and variations where the light source(s)are located within the vehicle in association with the vehicle rearviewmirror or otherwise positioned therein, the existing vehicle sideviewmirror assemblies need not be modified, other than adding mirror pitchand azimuth angle pickoffs to control sideview mirror positioning underfeedback control by the microcomputer. The eye location, sideview mirroralignment and air bag deployment adjustment may be implemented employingthe existing vehicle microcomputer or a separate inexpensive on-boardmicrocomputer.

The interior locations of the light sources avoids any problems ofpassing the light beam pair through the vehicle door windows in badweather or due to grime.

Through use of the alignment aids of the present invention, accuracy inpositioning of the sideview mirrors to reflect objects in the vehicleblind spot and driver appreciation of the proper mirror settings aregreatly increased, hopefully resulting in lower frequency of accidentsand injury. In each case where sideview mirror positioning signals arederived outside of direct control by the driver, the driver may beprovided with the ability to manually override the sideview mirror pitchand azimuth settings for safety reasons.

The risk of injury due to airbag deployment force may be diminishedthrough correlation of the airbag deployment force and duration to thesize and location of a driver or passenger in the driver's orpassenger's seat as determined in accordance with the teachings of thepresent invention.

This summary of the invention and the objects, advantages and featuresthereof have been presented here simply to point out some of the waysthat the invention overcomes difficulties presented in the prior art andto distinguish the invention from the prior art and is not intended tooperate in any manner as a limitation on the interpretation of claimsthat are presented initially in the patent application and that areultimately granted.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, advantages and features of the present invention will bereadily appreciated as the same becomes better understood by referenceto the following detailed description when considered in connection withthe accompanying drawings, in which like reference numerals designatelike parts throughout the figures thereof and wherein:

FIG. 1 is a top plan schematic view showing the basic geometry involvedin the angular, horizontal azimuth adjustments of a sideview vehiclemirror achieving a correct alignment that reflects light from objects inthe vehicle blind spot;

FIG. 2 is a two-dimensional plan view showing the sideview mirrorincorrectly aligned so that the driver cannot see objects in thevehicle's blind spot;

FIG. 3 is a simplified perspective illustration of a sideview mirrorassembly used in one variation of the first preferred embodiment of theinvention wherein the light source located therein is fixed in position;

FIG. 4 is a simplified perspective illustration of the sideview mirrorassembly of FIG. 3 modified to depict one simple means of spreading thereflected light beam pair to compensate for varying driver heights;

FIG. 5 is a simplified system block diagram illustrating amicrocomputer-based system for locating the driver's eye location foruse in vehicle control systems and for effecting the adjustment of thevehicle sideview mirror assemblies in accordance with the firstpreferred embodiment of the invention;

FIG. 6 is a simplified perspective illustration of a sideview mirrorassembly used in one variation of the second preferred embodiment of theinvention wherein the light source located therein itself adjustable inpitch and azimuth;

FIG. 7 is a simplified system diagram illustrating a microcomputer-basedsystem for locating the driver's eye location for use in vehicle controlsystems and for effecting the adjustment of the vehicle sideview mirrorassemblies in accordance with the second preferred embodiment of theinvention;

FIG. 8 is a simplified top plan schematic view of correctly alignedsideview mirrors in either the first or second embodiment showing both aleft hand and a right hand mirror affixed to the vehicle and thedetermination of the driver's eye location;

FIG. 9 schematically illustrates other locations of the light source andassociated components of the second embodiment of the invention insidethe vehicle;

FIG. 10 is a simplified system diagram illustrating amicrocomputer-based system for locating the driver's eye location andfor adjusting the vehicle sideview mirrors in accordance with the secondembodiment of the invention wherein the light source is located in oneof the positions illustrated in FIG. 9, for example,

FIG. 11 and 12 simplified diagrams of a doublet auxiliary mirror forreflecting a fixed light beam pair into driver's eyes mounted inrelation to the vehicle interior rearview mirror and pitch and azimuthpickoffs mounted to the rearview mirror gimbal mechanism for measuringthe pitch and azimuth mirror angles of adjustment causing the light beampair to be reflected into the driver's eyes;

FIGS. 13 and 14 simplified illustrations of the direction of the lightbeam pair and reflected image of the rearward scene into the driver'seyes with azimuth adjustment of the rearview mirror;

FIG. 15 is a simplified illustration of the direction of the light beampair and reflected image of the rearward scene into the driver's eyeswith pitch adjustment of the rearview mirror;

FIG. 16 schematically illustrates a system for locating the driver orthe front seat passenger and for controlling airbag deployment force andduration as a function of the determined locations;

FIG. 17 is a schematic illustration of a housing for a light beam pairthat is useable in FIGS. 3-16; and

FIG. 18 illustrates the relationship of the light beam pair to the eyesof a driver of a vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Introduction

In the following, a method and apparatus is disclosed for locating thedriver's eye location and optionally, the front seat passenger's eyelocation, involving adjustment of the direction of a light beam from asingle light source or the directions of two or more light beams fromtwo or more spatially separated light sources, in each case emitting alight beam pair comprising a right eye light beam and a left eye lightbeam. Several variations are presented as to the nature, location(s) andadjustment mechanism(s) for adjusting the light source(s) so that lightbeam(s) are visible to the driver's (or passenger's) eyes. It is oneprincipal purpose of the invention to employ the derived locations incontrolling vehicle safety and comfort systems, e.g., controlling thedeployment of vehicle airbags in the event that a collision occurs. Itis a further principal purpose of the present invention to deriveexterior vehicle sideview mirror adjustment signals from the location ofthe driver's eyes, so that the sideview mirrors reflect images of thevehicle blind spots to the driver's eyes. The derivation of the driverseye location and the employment of same in the adjustment of vehiclesideview mirrors will first be described.

The blind spot or blind zone for a specific vehicle having specificsideview and interior rearview mirror styles is fixed and can bedetermined a 'priori by the mirror manufacturer. This is an approximateassumption, as the actual blind spot location will be somewhat affectedby the relative displacement in three dimensional space between aparticular driver's eyes (to be more precise, the center point betweenthe driver's left eye and right eye) and a suitable mirror referencepoint at which the driver is looking.

As is well known, a driver intuitively looks at the center of the mirrorwhen aligning a mirror. Furthermore, the intersection of the mirror'spitch and azimuth rotation axes constitutes a true pivot point, whichremains stationary with respect to the housing regardless of mirroradjustment. For most mirrors, the location of this pivot point can beconsidered to be at or very near the center of the sideview mirror'sreflective surface. Hereafter, the location of the mirror referencepoint will be considered coincident with the center of the mirror andthe mirror pivot point.

The nominal location (referenced to the center of the mirror) of theblind spot is a function of the width (end to end) and height (top tobottom) of the sideview mirror, the known vehicle dimensions, thelocation where the sideview mirror housing is mounted to the vehicle,the angular field of view that the interior rear view mirror covers(perhaps, more properly, does not cover), and the ranges of possibleseat heights, seat back angle adjustments, fore-aft seat positions, anddriver population heights. With consideration of these variables,appropriate mathematical formulae or algorithms may be used by themirror manufacturer to determine, a 'priori, a best estimate for adirection vector (unit vector) pointing from the mirror reference pointto the nominal center of the blind spot. These mathematical formulae oralgorithms are based on the simple laws of ray optics as applied toreflection from a mirror surface and are well known to those practicingin the art of automotive mirror design.

In preferred embodiments of the present invention relating to theadjustment of the vehicle sideview mirrors and in all their variationsthe exact blind spot direction vector (unit vector), rather than anominal or approximate direction vector, pointing from the mirrorreference point to the center of the blind spot, can be determined.While the change in the blind spot direction vector normally representsonly a small “second order” departure from the nominal direction thiscorrection is possible to implement whenever the exact location of thedriver's eyes is calculated by a microcomputer. In this case, since thecenter of each sideview mirror is fixed in the same vehicle body frameof reference the exact blind spot direction vector can be computed inreal-time or simply looked up from a stored table of pre-computedresults. The exactly correct, or more precisely, optimal, mirrororientations in pitch and azimuth for the particular driver's eyelocation in the vehicle can then be determined, and the mirrorautomatically driven to those angular positions.

In all the preferred versions of the first and second embodiments of thepresent invention and in all the variations thereof, the driver's eyelocation (more precisely a center point located between the driver'seyes) is explicitly calculated. Hence, “second order” adjustments of theblind spot direction for differences in driver's stature and seatingposition are included. The determination of the correct mirror pitch andazimuth positions involves calculations by an on-board or vehiclemicrocomputer using mathematical formulae and/or algorithms based ondata stored in the form of look-up tables. These calculations must beperformed during the actual mirror adjustment process as conducted bythe vehicle driver rather than simply being used to determine the bestestimate for the blind spot direction vector a 'priori by the mirrormanufacturer. These formulae or algorithms are again based on the lawsof ray optics applied to mirror reflection and are well known to thosepracticing in the art of automotive mirror design.

The Light Beam Pair

In accordance with the present invention, attention is next directed toFIG. 17 which geometrically illustrates the use of a light beam paircomprising a right eye light beam 202 and a left eye light beam 204originating from a fixed or movable light beam housing 200 containing aright eye light beam source 206 and a left eye light beam source 208.The light emitted by the right and left eye light beam sources 206 and208 is directed through lens elements 210 and 212 that providerespective right and left eye light beam emitting locations that areoffset in the horizontal, azimuth, direction (or X coordinate) from oneanother and from the common adjustment X, Y, Z axes of the light beampair. The right and left eye light beams 202 and 204 are nominallydirected in the same direction but diverge apart slightly in the azimuthdirection from the nominal Z axis as shown in FIG. 17 that is designatedthe light beam pair direction 218 in FIG. 18.

The light sources 206 and 208 may constitute high brightness LEDsencased within the housing 200 or may constitute the terminations oflight pipes or cables from a remote common high intensity light sourceor from remote separate color high-intensity light sources. In thelatter case, the end of the fiberoptic cable, suitable cleaved andlensed, would constitute a virtual light source within cavities of thehousing 200. In any case, the right and left eye light beams 202 and 204should be bright enough to be seen in daylight and distinctive in colorwhile not so bright as to damage the driver's or passenger's eyes.

FIG. 18 illustrates a generic manner in which the driver or passenger ofa vehicle can view the light beam pair 202 and 204. As shown in FIG. 18,the directions of the right and left eye light beams 202 and 204 areadjustable in tandem by the driver 220, the adjustments in pitch andazimuth about pitch and azimuth light beam adjustment axes having knownCartesian coordinates. The driver or passenger 220 adjusts the right andleft eye light beams 202 and 204 using a remote control 222, forexample, in tandem until they impinge upon the respective left eye andright eye with perceived maximal equal intensity. The driver 220 thensignals the microcontroller through remore control 222 to take thepickoff readings, and the nominal adjustment azimuth vector 218 can thenbe determined from the pickoff readings. In this way, the angularadjustment of the light beam housing is detected, and the loctation ofthe driver's or passenger's eyes is computationally derived as a set ofCartesian coordinates from the tandem adjustment of the binocular lightbeams and other known Cartesian coordinates of the vehicle.

First Preferred Embodiments

A summarized above, the first embodiment involves use of one or morefixed light sources emitting a respective light beam pair that isdeflected by a reflector until the light beam pair is visible to thedriver whereupon the driver's eye location may be derived. In a firstvariation illustrated in reference to FIGS. 1-5, each light source andreflector are associated with a vehicle sideview mirror. In a furthervariation illustrated in reference to FIGS. 11-15, a single light sourceand reflector are associated with a vehicle rearview mirror.

In the first variation of the first preferred embodiment illustrated inFIGS. 1-5, the a 'priori mathematical determination of the nominal blindspot direction with respect to the aforementioned mirror reference pointon the mirror surface is used to mount a narrow wavelength light sourceemitting a light beam pair in a fixed relationship with respect to thevehicle left and/or right sideview mirror housing. When properly mountedin the mirror housing, the Cartesian coordinates of the light sourcereferences the vehicle longitudinal (fore-aft) axis, the vehicle'svertical axis perpendicular to the road surface, and a transversehorizontal vehicle axis, so that the light beam pair is launched at thenominal blind spot in the azimuth direction.

Both the fixed pitch and azimuth light beam launch directions are setduring fabrication of the mirror assembly with respect to the knowncharacteristics of the vehicle and driver population taken into accountas described above. For most vehicle applications, the pitch launchdirection will be close to horizontal as only small pitch angles, saywithin ±10 degrees of horizontal, are typically involved in mirroralignment. Furthermore, because near optimal pitch alignment of thedriver's side mirror is relatively easy to achieve for most drivers,even manually, the following discussion shall be directed initially toshow how the first preferred embodiment improves azimuth alignment ofthe driver's sideview mirror.

The mirror reference point, the light source center, and the light beampitch and azimuth launch directions are all fixed with respect to thevehicle frame. An auxiliary mirror attached to the main mirror causesthe light beam pair to be deviated into the driver's eyes as he/shemanually adjusts the driver's sideview mirror. When the intensity of theright and left light beams are equalized and maximized in the driver'seyes, appropriate mirror adjustment pitch and azimuth angle measurementpickoffs read the pitch and azimuth orientation of the mirror withrespect to the vehicle frame and then input these azimuth and pitchmeasurements to a microcomputer. This information may then be employedto locate the location of the driver's eyes.

Knowing the Cartesian coordinates location of the driver's eyes allowsfor a “second order” correction of the driver's side mirror orientationautomatically by the microcomputer to accommodate drivers of differentstature or having preferred seating positions from a “nominal” orhypothetical driver. Further, knowledge of the driver's eye location canbe used, in more complex variations of the first embodiment, topartially or totally automate the settings of the second (passenger's)sideview mirror. In addition, knowledge of the driver's eye location maybe useful for other purposes, such as airbag deployment control.

In the context of this variation of the first embodiment, FIGS. 1 and 2are schematic illustrations of the concept and theory of the proper andimproper azimuth adjustment of the driver's side sideview mirror. FIGS.3 and 4 illustrate in simplified views the mechanical configuration ofthe improved mirror assembly of the first embodiment for providing thecorrect azimuth alignment and allowing a range of pitch adjustment tocompensate for driver eye level height variation. FIG. 5 schematicallyillustrates a microcomputer-based system for locating the driver's eyelocation for use in vehicle control systems and for effecting theadjustment of the vehicle sideview mirror assemblies in accordance withone variation of the first preferred embodiment of the invention.

Turning to FIG. 1, it shows a schematic, top plan view of the basicgeometry involved in the first embodiment of the invention with respectto a vehicle 10 with a driver 12 sitting inside and a sideview mirror 20in correct alignment to reflect the image of the blind spot 30 into thedriver's eyes. For simplicity of description, the light beam emitter 40is depicted and described as a single light beam emitter in the figures.

The optical rays 32 to the driver's eyes from the blind spot 30 and theLED light beam 42 emitted by LED 40 during the adjustment for a properlyaligned sideview mirror 20 are depicted. Any variations in driver heightand required small adjustments in vertical alignment (i.e. in mirrorpitch) are not accounted for in FIG. 1 for simplicity of explanation.

As also shown in FIG. 3, the main sideview mirror 20 is attached to amuch smaller, stubby “auxiliary” mirror 24 projecting at 90° from itsback side to form a mirror subassembly 25. The sideview mirror 20 has aprimary reflective front surface 26 facing outward of the mirror housing22 (depicted with an outward extending mirror normal vector 74) and asecond interior or back surface and may be of any conventionalconfiguration and construction. The auxiliary mirror 24 (depicted withan outward extending normal unit vector 78, perpendicular to the mirrorsurface) is mounted to the back surface at right angles to the plane ofreflective surface 26 near the center of the sideview mirror 20 andextends into the mirror housing 22. The auxiliary mirror 24 has areflective mirror surface 28 at 90° to the main mirror surface 26. Theauxiliary mirror 24 changes the azimuth direction of the light beam 42by 90° when and only when the main mirror surface 26 is orientedproperly in azimuth so as to reflect rays from objects in the blind spotinto the driver's eyes. When the sideview mirror 20 is properly alignedin azimuth, both rays 32 from the blind spot and the beam of light 42are directed to the driver's eyes.

For the reflected light beam 42 to be transmitted through the sideviewmirror 20 and seen by the driver 12, a small, central region 21 of themirror surface 26 is not totally reflective but is transparent, or atleast semi-transparent, or otherwise selectively transmissive to thewavelength of the light beam 42 employed. The selectively transmissiveregion 21 may be readily achieved in a number of ways.

One method is by fabricating the mirror surface 26 using properlyselected layers of thin dielectric films which reflect all wavelengthsexcept the selected wavelength of the light source 40. The only region21 where the dielectric layer stack would actually have to permit thenarrow band light beam to pass is shown in an exaggerated size in dashedlines in FIGS. 3 and 4. Therefore, the sideview mirror 20 would onlyhave to be selectively transmissive to the wavelength of the light beamin the selectively transmissive region 21. The art of making suchwavelength selective reflectors is well known to thin film coatingspecialists engaged in multi-layer dielectric mirror fabrication asshown, for example, in the above-referenced '167 and '085 patents.

An alternate, perhaps simpler, method for achieving transmission of thelight beam 42 through the selectively transmissive region 21 can beemployed by varying the silver metal deposition process. In this method,the small region 21 (typically a few mm on a-side) would be left notsilvered or only partially silvered. Such techniques are well known tothose skilled in the art of metal film mirror fabrication. In this case,the not-silvered, or partially silvered, light transmissive region 21 istransmissive of all light wavelengths or “white” light. However, inpractice, only the light emitted by the light source 40 would bepresent, when energized, within the mirror housing 22 and visible to thedriver through the region 21 when the sideview mirror 20 is properlyaligned. At other times, the selectively transmissive region 21 wouldappear as a small black dot on the otherwise reflective mirror surface26. For this reason, using this or similar methods of fabrication of aregion that would pass a wider band or all wavelengths of visible lightstill results in a selectively transmissive region 21, for all practicalpurposes. The expression “selectively light transmissive region” istherefore intended to include any such fabrication technique andresulting structure and technical equivalents thereto. Similarly, theexpression “selective wavelength” is intended to include narrowbandwidths and full “white” light depending on the construction.

With approximately correct alignment of the exterior sideview mirror 22by the vehicle driver 12, central rays 32 from the blind spot image area30 reflected from mirror surface 26 and the reflected alignment lightbeam 42 transmitted through the selectively transmissive region 21 arecollinear when directed to the driver's eyes, as shown in FIG. 1. Thedriver 12 will see both the bright spot of the narrow bandwidth lightbeam 42 as well as the reflected blind spot image area 30. Thiscollinear condition is not exact when driver height and fore-aft seatposition is considered, but is still approximately correct, as will bediscussed shortly. In the first embodiment of the current invention,this small error in proper mirror alignment is subsequentlyautomatically eliminated after the exact location of the driver's eyesis determined by the microcomputer 52 of FIG. 5.

On the other hand, when the sideview mirror 20 is substantiallymisaligned, the vehicle driver 12 no longer sees the alignment lightbeam 42, or at least the radiation intensity entering the driver's eyesis much reduced from that occurring under correct mirror alignment. FIG.2 is again a two-dimensional plan view as in FIG. 1, but showing theeffect of incorrect alignment of the driver's side or left sideviewmirror 20. Due to the incorrect alignment, the driver 12 would not beviewing traffic in the vehicle's blind spot if he/she looked into themirror 20. The LED light beam 42 is reflected away and would not be seenby the driver 12 in this incorrect mirror position.

FIG. 3 shows a simplified mechanical assembly drawing of this firstpreferred embodiment of the opto-electronic aid for alignment ofautomotive exterior sideview mirrors. As noted, the LED 40 is fixed tothe stationary mirror housing 22, and the light beam 42 points into the“nominal” blind spot area 30 (as stated earlier really a conical shapedvolume). The reflection of the light beam 42 afforded by the smallauxiliary mirror 24 through the selectively light transmissive region 21(shown dotted) of the sideview mirror 20 is depicted. The sideviewmirror 20 is supported for rotation about the horizontal or pitch andvertical or azimuth mirror axes 37 and 39.

The actual size of the auxiliary mirror 24 can be quite small, on theorder of 0.5″ wide by 0.5″ high by 0.1″ thick. It should also be notedthat the auxiliary mirror 24 used in the first preferred embodiment doesnot have to be a physical mirror. Instead, mirror 24 could be a 90°corner cube reflector, suitably mounted on the back side of sideviewmirror 20. Alternately, mirror 24 could be a mechanically ruled orholographically formed diffraction grating placed on the back surface ofthe sideview mirror 20, where the appropriate diffraction order wouldredirect the light beam 42 by 90° and then through the selectively lighttransmissive region 21.

In regard to all of the described embodiments, it should be noted that,depending on the mirror design and mirror mounting system used, thepitch and azimuth mirror axes 37 and 39 may not be truly horizontal andvertical, respectively, as measured against the force of gravity, noreven be exactly orthogonal to one another. Rather, horizontal andvertical as used herein must be considered as nominal directions.However, whatever their exact orientation with respect to each other andgravity, the axes 37 and 39 are constants in any given mirrorsubassembly 25 and vehicle.

For illustration clarity, the sizes of the mirror alignment aidcomponents are exaggerated in FIGS. 1-3. The reflection of light beam 42is actually much closer to the “root” (the junction line between the twomirrors 20 and 24). Furthermore, the root and the selectively lighttransmissive region 21 are displaced in FIGS. 1-3 for ease ofillustration. In practice, they are virtually coincident with thepreviously described mirror reference point on the front surface of themirror at or very near the center of the mirror 20 and at or near theintersection of the pitch and azimuth mirror axes 37 and 39. Therefore,in reference to FIG. 3, under a condition of proper alignment, the lightbeam 42 reflects from the reflective mirror surface 28 near its “root”with the sideview mirror 20 and is transmitted through the selectivelylight transmissive region 21 of the sideview mirror 20 and through thevehicle 10 window into the vehicle interior. When the driver sees thetransmitted light beam 42, the mirror reflective surface 26 is properlyaligned to reflect the rays 32 of the vehicle blind spot 30 on that sideof the vehicle.

It should be noted that the LED light beam 42 is, in practice, not thecollimated pencil beam shown for simplicity in FIG. 3 but ratherdiverges into a radiation cone. Thus, reasonably small, random motionsof the driver's head may occur, while the main LED beam 42 will still bemaximized in the driver's eyes when the mirror 20 is properly aligned.

Examining FIGS. 1-3 further, it should be noted that the LED 40 pointsat the “nominal” blind spot 30 in azimuth. On the other hand, the LED 40should not actually point at the “nominal” blind spot 30 in pitch, atleast if the auxiliary mirror 24 is only a single surfaced mirror asshown. Rather the LED 40, or other light source, beam 42 should beangled upwards in pitch to the same amount (in degrees) that a nominaldriver would want his or her view of the blind spot in the center of themirror to be angled downwards.

To understand this, consider the following. The driver's eyes areusually higher than the horizontal pitch axis 37. The blind spot 30 isusually slightly below the level of the mirror subassembly 25, i.e.closer to the surface of the road. This is also usually below thedriver's eye level. Thus, in order for the LED light beam 42 to beapproximately collinear with the central ray 32 from the blind spot 30,as seen by the driver 12, the LED light beam 42 must to actually beangled a small amount upwards corresponding to the nominal small upwardangle of the direction vector (unit vector) 66 pointing from the mirrorreference point to the location point of a typical driver's eyes 80.Once identified mathematically or empirically, this nominal upwardspitch adjustment of LED 40 can be fixed for a given mirror style andvehicle model.

When angled slightly upward, the LED light beam 42 will continue to riseinto the driver's eyes upon reflection from the auxiliary mirror 24through the selectively transmissive region 21. This path is similar tothe path in which the light ray 32 from the image in the blind spot 30are deviated upwards into the driver's eyes by the action of the mainmirror reflective surface 26. In the event that the mirror is highmounted on the particular vehicle so that a typical driver's eyes arenominally below the mirror center, the LED beam 42 would, of course,have to be angled down rather than angled up.

From the geometry depicted in FIGS. 1-3, it should also be noted thatthis first preferred embodiment is fairly insensitive to driver fore-aftseat placement although not totally insensitive. In particular, thefixed LED 40 always launches its light beam 42 toward a nominal blindspot. Regardless of where the driver is sitting, objects in this nominalblind spot will be reflected into the driver's eyes after the mirror isaligned using the LED 40. As noted, the actual blind spot location andhence the optimal azimuth orientation of the mirror will depend somewhaton the driver's stature and fore-aft seating position. Normally thisshift in actual blind spot location with driver fore-aft seat positionis very small, and in some versions of the first embodiment described inthe parent patent application this shift was ignored. There, thedriver's eyes were always directed at the nominal blind spot. In thefirst embodiment of the current invention, any shift in blind spot withdriver stature and fore-aft seating position is totally compensated for.

Turning now to adjustments in pitch made for driver height or selectedseat height position, this usually requires a slight rotation of thesideview mirror 20 about its nominally horizontal pitch axis 37 from acondition of being exactly vertical. In the first preferred embodiment,the central rays 42 and 32 of the LED 40 and blind spot 30 willtherefore not quite be collinear when they enter the driver's eyes atthe extremes in height/seat position, at least when only a singleauxiliary mirror 24 is employed.

A more complicated “doublet” auxiliary mirror, of the type describedbelow with reference to FIGS. 11-15, possessing two orthogonalreflecting surfaces, could eliminate the problem of non-co-linearity inpitch between the blind spot imagery and the alignment beam. Inparticular, a doublet auxiliary mirror will be shown as part of aninterior rearview mirror assembly used in one variation of the secondpreferred embodiment later in this patent continuation application.However, fabricating and installing a doublet mirror in an exteriorsideview mirror where only very minimal pitch adjustments from verticalare required in the first place may not be cost effective and onlyunduly complicates the present discussion. What remains to consider,then, is how different driver height/seat height positions, and henceeye levels, may be accommodated in this first preferred embodiment withminimum reduction in azimuth alignment accuracy, even though only asingle surfaced auxiliary mirror is employed.

As noted above, depending on the amount of driver eye level variationfrom the design norm for the particular vehicle, the sideview mirror 20will have to be tilted plus or minus a few decrees from its nominalpitch orientation. The following modification to the first embodimentwill work well with mirror designs in which the nominal pitch angle isnear 0° or true vertical.

FIG. 4 shows this modification involving simply diverging the LED lightbeam 42 to encompass the variety of driver eye levels typicallyencountered. It is only necessary to insure that the LED light beam 42spreads adequately in the vertical direction so that both tall and shortdrivers, even in the extreme seat positions, will see the beamapproximately maximized when the mirror 20 is properly aligned in theazimuth direction.

Non-uniform divergence of the reflected light beam 42 is frequentlyalready associated with many LEDs 40. In this case, it may only benecessary to align the LED 40 on its mount so that the greater inherentlight beam divergence is along the vertical direction. If still morevertical divergence is necessary, a simple anamorphic or flat Fresnel orminiature glass rod lens (so-called SELFOC lens) 61 can be placed on theend of the LED 40 to produce the desired somewhat elliptical beam spotpattern. Typically, a 5°-10° divergence cone would be appropriate. FIG.4 shows such a lens 61 mounted on the LED 40 to properly shape thereflected light beam 42 into the depicted elliptic pattern as seenwithin the driver's compartment.

In this first embodiment of the present invention, the LED light beam 42launch angle is not changed as the driver 12 tilts the sideview mirror20 to compensate for variations in driver height. Hence, the degree ofco-linearity of the LED beam 42 and true blind spot image rays 32 isagain reduced just as with driver fore-aft seat adjustment. Since only asmall range of mirror 22 pitch tilt should encompass all driver heights,this slight reduction in exact co-linearity of the LED and blind spotcentral rays should be quite tolerable when additional spreading of theLED beam 42 in the vertical direction is introduced as described withrespect to FIG. 4. The vertical spread of the light beam 42 makes iteasier for the driver 12 to see the light beam as the mirror azimuthchange is being made. Then, the driver 12 can readily maximize theintensity of the LED beam 42 in his or her eyes by operating the mirrorpitch control and can be assured that any residual azimuth misalignmentfrom driver eye height effects will be very small.

It should also be noted in this regard that most drivers are able toeasily visually determine the pitch adjustment that provides a nearoptimum view rearward from the reflected blind spot image 30. Pitchalignment is correct when the driver sees neither the sky nor the roadsurface immediately behind the vehicle but rather is able to view thehorizon behind the vehicle, approximately centered m his/her field ofvision in the sideview mirror.

All of the FIGS. 1-4 are schematic and exaggerated in certain details toillustrate and ease the understanding of the principles of blind spotsand certain aspects of the invention. The particular joystick control,suspension of the mirror subassembly 25 within the mirror housing 22that allows adjustments in pitch and azimuth, and the mechanism employedto make the adjustments are not shown in FIGS. 1-4. This is for ease ofillustrating the principle components and operation of the firstembodiment. It should be understood that a ball swivel joint, pitch andazimuth gimbals or any of the known, remote control electro-mechanicalmirror adjustment systems, including those shown in any of theabove-referenced patents, could be employed to provide a suitablesuspension of the mirror subassembly 25 and adjustment mechanism forproviding adjustment of the mirror pitch and azimuth.

Turning to FIG. 5, it depicts a system for the determination of thedriver's eye location employing one or two light sources which areenabled to emit light beams that are reflected by a reflector tointersect the driver's eyes in order to derive the driver's eyelocation, particularly to develop sideview mirror pitch and azimuthadjustment signals. The system of FIG. 5 may also be employed to derivethe driver's eye location for purposes of determining the height andfore-aft distance of the driver from the driver's side air bag, and touse that information to adjust the airbag deployment force and durationas described below with reference to FIG. 16. In addition, FIG. 5depicts the components of the system used for these purposes that may beemployed with the variation of the first embodiment described below withreference to FIGS. 11-15. FIG. 5 also depicts the common components ofsuch systems of the first embodiment required for both a purelyopto-mechanical alignment aid and for the more complex, automatedsideview mirror adjustment system described in the first preferredembodiment of the present invention.

In the comprehensive system of FIG. 5, the mirror assembly 27 isdepicted in relation to the alignment aid control assembly 50 including,a joystick control 54 and optionally including a vehicle or on-boardintegrated microcomputer 52 and input/output signal lines. The mirrorassembly 27 includes the mirror subassembly 25 supported on mirror pitchand azimuth gimbals 33 and 35. The mirror adjustment in relation to theLED 40, fixed in position in the mirror housing 22, is effected bymirror pitch and azimuth servo motors 34 and 36. The mirror pitch andazimuth gimbals 33 and 35 allow the rotation of the mirror subassembly25 about the nominally horizontal and vertical mirror axes 37 and 39,respectively, in response to pitch and azimuth servo motor drivesignals.

The mirror assembly 27 of the system depicted in FIG. 5 may beduplicated for both the right and left exterior sideview mirrors.Separate joystick controls 54 or a sequential operation of the joystickcontrol 54 may be provided to control the pitch and azimuth alignment ofeach mirror subassembly 25 in the manner described below. Thecomprehensive alignment aid control assembly 50 depicted in FIG. 5preferably comprises the joystick control 54 and a button 56 powered bythe vehicle battery 58 when ignition auxiliary power switch 60 isclosed, the switching network 64, button 56 and microcomputer 52.

The mirror adjustment joystick control 54 in this variation of the firstembodiment serves to provide illumination power to the LED 40 anddirectly adjusts the mirror 20 in tilt or pitch and azimuth, the lattersimilar to operation of an ordinary exterior power sideview mirror. Inthe depicted comprehensive embodiment of FIG. 5, the joystick control 54provides an LED power signal to the LED 40 and servo motor drive signalsto the servo motors 34 and 36 directly (bypassing depicted switchingnetwork 64) during an adjustment. As described above, the initial manualmirror adjustment may alternatively be accomplished via a cableextending from the joystick control 54 to a mechanical linkage foradjusting a known ball joint mirror pitch and azimuth support mechanismmounted in the mirror housing 22.

In this variation of the first-embodiment of the present invention thevehicle or onboard microcomputer 52 is interfaced through the button 56and switching network 64 as shown in FIG. 5 to provide simple on-offcontrol and memory functions and to compute the driver's eye location,update the blind spot direction to be consistent with the computeddriver's eye location, and direct the sideview mirror through servocontrol to reflect the desired imagery into the driver's eye regardlessof driver stature and seat position. In this regard, the mirror pitchand azimuth gimbals 33 and 35 or servo motors 34 and 36 also includeangular measurement means or pickoffs 38 and 41, respectively, forproviding mirror pitch and azimuth angular position data to themicrocomputer 52. The pickoffs 38, 41 are miniaturized angle resolvers,and may be rotary optical encoders, preferably using absolute encoderdisks of the type disclosed, for example, in the article “Principles ofRotary Optical Encoders”, appearing in SENSORS, April 1993, pp. 10-18.

Particularly in original equipment manufacture applications, the vehicleor on-board microcomputer 52 may be also be used to memorize the pickoffsignal values after a driver has once aligned each mirror and thengenerate the optimal pitch and azimuth mirror alignment signals for thesideview mirror(s) on subsequent occasions in a “memory” mode ofoperation. The object here is to avoid requiring the driver torepeatedly realign the side view mirror(s) after having already donethis once before, even if another person has driven the car since thenand has changed the mirror alignment. Apart from the pickoffs 38, 41 andmicrocomputer 52, all that is required is a suitable identificationcode, card or key for each driver and an entry system interfacing withthe microcomputer 52. The microcomputer 52 may also be operational toreceive seat position data and other vehicle data that is personalizedto the ID code of the driver as shown in FIG. 5. Finally, the driver'seye location computed by the microcomputer 52 may also be stored andused for airbag deployment control settings and other vehicle systemcontrol functions such as radio, heater, seats, etc., assuming that thedriver inputs an ID code upon entering the vehicle.

Another variation of the first embodiment (that also requiresmicrocomputer 52 and that may be implemented with or without the memorymode) allows for elimination of the LED 40, selectively lighttransmissive region 21, and auxiliary mirror 24 in the passenger sidemirror. Instead of using the light beam 42, the passenger's sideexterior sideview mirror would be aligned based on the results of thedriver's side sideview mirror alignment, in particular, on the resultsof the driver's eye location computation. Alignment of the passenger'sside sideview mirror would be completely automatic under computercontrol using pitch and azimuth servo motors and pitch and azimuth anglemeasuring pickoffs installed as part of the second mirror assembly longwith certain other assumptions. This additional variation of the firstembodiment will be discussed after the second embodiment is describedand in reference to FIG. 8, since the required computations involve thesame equations as are solved in the second embodiment

The method by which the system of FIG. 5 may be employed to refine thepitch and azimuth position achieved by the driver's initial adjustmentof the sideview mirror will now be described. After the driver hasmanually adjusted the sideview mirror 20 to maximize the intensity oflight beam 42 by adjusting the mirror's azimuth angle, and after he/shehas adjusted the mirror 20 to an acceptable pitch angle, the firstpreferred embodiment of the current invention goes into an automaticmode to refine the alignment. In particular the microcomputer 52 of FIG.5 uses the mirror pitch and azimuth angle determination pickoffs 38 and41 to measure the pitch and azimuth angles and then determines thedriver's eye location. The mathematics involved are the same as for thesecond preferred embodiment described below and are described below. Inturn, this allows a more accurate “second order” assessment of the trueblind spot location with respect to the vehicle.

Next, refined pitch and azimuth orientation angles are computed for thesideview mirror 20 so as to produce the proper blind spot imagery for adriver of a given stature and seating position as opposed to one ofnominal stature seated in some nominal position behind the steeringwheel. Again, the mathematics are the same as for the second preferredembodiment and are described below. The microcomputer 52 then derivespitch and azimuth adjustment signals that are applied to the pitch andazimuth servo motors 36 and 34 to adjust the mirror to these optimalpitch and azimuth angles automatically using the closed loop feedbackcontrol system.

Second Preferred Embodiment

Before discussing the second variation of the first embodiment,attention is directed to the first variation of the second preferredembodiment and FIGS. 6 -8 wherein a light source 40 is associated withat least one of the vehicle sideview mirrors, as in the first variationof the first embodiment. In this second embodiment, the driver'smanipulation of the joystick control 54 of FIG. 7 now directly adjuststhe LED 40 (or other light source) light beam 42 direction, not thepitch and azimuth of the sideview mirror 20. In the system illustratedin FIGS. 6 and 7, the LED 40 is mounted for movement about pitch andazimuth axes within a sideview mirror assembly 27 in relation to aselectively light transmissive region 21 of the mirror 20. It should benoted that in a second variation of the second embodiment illustrated inFIGS. 9 and 10 and described in detail below, the LED 40 is mounted formovement about pitch and azimuth axes at a mounting point within thevehicle cabin. In either variation, the system may include a second LED40′ mounted in the other sideview mirror assembly or elsewhere in thevehicle. These systems may be used to derive the driver's eye locationor the passenger's eye location. These derived locations may be employedin the derivation of sideview mirror adjustment signals and/or in thecontrol of the vehicle airbag system as summarized above and describedin detail below.

FIG. 6 shows a simplified mirror subassembly 25 of the mechanicalcomponents of this first variation of the second preferred embodiment ofthe invention with the LED 40 incorporated into the mirror subassembly25 as in the embodiment depicted in FIG. 5. Note in FIG. 6, that the LED40 is mounted on a set of LED pitch and azimuth gimbals 43 and 45,respectively, rather than directly mounted on the mirror housing 22.Also note that the LED beam 42 is directed toward the driver through theselectively light transmissive region 21 and not reflected off anauxiliary mirror. The latter is not necessary and would only complicatethe mathematics involved in this second embodiment. The outer, LEDazimuth gimbal 45 permits rotations of the LED 40, and hence LED lightbeam 42, about a vertical 49 to adjust for driver fore-aft seatposition. The inner, LED pitch gimbal 43 allows for the LED 40 to betilted up or down with respect to the driver's eye level about ahorizontal axis 47.

In this first variation of the second preferred embodiment, thealignment process is therefore accomplished by first directing thenarrow wavelength LED beam 42 through the sideview mirror's selectivelytransmissive region 21 from the backside and toward the driver. Thisrequires suitable fabrication of the mirror reflective layers in theregion shown in dashed lines in FIG. 6 in the same manner as describedabove. For ease of illustration, the selectively transmissive region 21is shown off center from the mirror reference point in FIGS. 6 and 7.

Turning to FIG. 7 it will first be described in the context of use forderiving the driver's eye location and properly adjusting the pitch andazimuth angles of the vehicle sideview mirrors. In FIG. 7, when thedriver 10 indicates that he/she sees the narrow wavelength LED beam 42by depressing button 56, the microcomputer 52 solves a-set ofmathematical equations and/or performs a table look-up operation anduses the resulting position data to drive the mirror servo motors 34 and36. Servo motors 34, 36 set the pitch and azimuth angles of the mirror20 in the correct alignment to reflect objects in the vehicle blind spot30 into the driver's eyes. In this embodiment, the compensations fordriver eye level variations and fore-aft seat placement is exact in theresultant mirror follow-up alignment.

The sideview mirror 20 is supported on the two mirror alignment gimbals33, 35 coupled to the mirror servo motors 34, 36. The LED pitch andazimuth adjustment servo motors 46, 48 track the driver's manualadjustment of control knob 62 to maximize the LED beam intensity at thedriver's eyes. The LED pitch and azimuth angle measurement pickoffs 51and 53 on the LED servo motor gear drives provide LED: pitch and azimuthangle feedback signals to the microcomputer 52. The mirror alignmentservo motors 34, 36 respond to the microcomputer derived pitch andazimuth mirror drive signals to drive the two mirror gimbals 33, 35 andperform the actual alignment of the sideview mirror 20 with the blindspot.

In particular, the mirror alignment servo motors 34, 36 operate undermicrocomputer 52 control to align the sideview mirror 20 to the properpitch and azimuth orientation determined from the final alignment of theLED light beam 42 axis with the driver's eyes. This includescompensating for any shift in the blind spot direction with variationsin driver height or fore-aft location of the driver's eyes. Toaccomplish this compensation, the location of the driver's eyes 80 mustbe computed in all versions of the second preferred embodiment.

The mirror pitch and azimuth angle measurement pickoffs 38, 41 providefeedback position signals to the microcomputer 52. These feedbackcontrol signals provide the microcomputer 52 with the information neededto determine the direction and amount of pitch and azimuth adjustment ofthe sideview mirror 20 required to achieve optimal mirror alignment withthe blind spot 30. The automatic mirror positioning system of FIG. 7constitutes a closed loop angular positioning servo control system. TheLED beam 42 direction is adjusted by the driver via the joystick control54 as described above. Once the driver sees the LED beam 42, he or shemaximizes its intensity by fine tune operating the sideview mirrorcontrol knob 62 and then depresses the button 56.

The button switch 56, is typically on the same mirror control joystick54. This “pickle” button feature is well known in the art of video gamehardware design. When the button switch 56 is pressed, the microcomputer52 removes power from the LED 40 to extinguish the light beam 42. TheLED gimbal pitch and azimuth angles, Θ_(L) and Φ_(L) respectively, arethen read out via the pitch and azimuth pickoffs 48 and 51.

The LED gimbal pitch and azimuth angles Θ_(L) and Φ_(L) are simply theEuler angles, relating a transformation of coordinates between a mirrorhousing fixed Cartesian coordinate system establishing the mirrorazimuth or vertical axis 39 and the mirror pitch or horizontal axis 37and a second Cartesian coordinate system establishing the LED azimuth orvertical axis 49 and the LED pitch or horizontal axis 47. Given thesetwo Euler angles, the microcomputer 52 is able to compute the threedirection cosines (p_(d), q_(d), r_(d)) which define a unit vector 66pointing from a suitable reference origin point on the LED 40, typicallyat the pivot center of the LED 40, towards the driver's eyes 80. (Thecorresponding displacement, or distance, vector between the driver'sside mirror 20 and the driver's eyes 80, shown in FIG. 8, is simply thelinear extension of unit vector 66 and is identified by the same number,66, in FIG. 8.) Each component of the three element, driver directioncosine vector 66 is the cosine of the angle between the unit vector 66toward the driver's eyes and the corresponding mirror housing fixedreference axis, i.e. the X_(v), Y_(v), Z_(v), vehicle axes usingCartesian axes.

In the practice of the first variation of the second embodiment in itsbasic form, the location of the driver's eyes 80 is determined asfollows. Given the above driver's eye direction cosines determined fromthe. LED gimbal pitch and azimuth angles Θ_(L) and φ_(L), a unit vectoris constructed from the LED 40 towards the driver 12. This vector isextended mathematically until it intersects a vertical fore-aft seatplane 82 in FIG. 8. To obtain a unique location for the driver's eyes itis only necessary to insure that the mount and axes allowing pitch andazimuth adjustment of the LED light beam 42 are not in the fore-aft seatplane. This is certainly the situation when the alignment LED 40 islocated in the exterior sideview mirror assembly 27 and is also the casefor many other potential locations for the LED 40 including locationsinside the vehicle such as near or on the interior rearview mirrorassembly.

In the case of the first embodiment described previously, a similardriver's eye direction cosine vector may be computed given the measuredpitch and azimuth angles associated with the sideview mirror 20, afterthe driver manually aligns the mirror using the fixed LED 40, and giventhe known fixed angular direction of the alignment light beam 42. Thisis merely a simple problem in ray optics under plane reflection from theauxiliary mirror 24. In either embodiment, the alignment light beam 42ends up being directed toward the driver's eyes 80 from a given fixedpoint relative to the vehicle cabin, i.e., the mirror reference point inthe first embodiment and the LED 40 pitch and azimuth axes, moregenerally, in the second embodiment. The intersection of the linearextension of this unit vector and the fore-aft seat plane 82, in whichthe driver is assumed to be centered regardless of stature and fore-aftseat position, determines the driver's eye location in vehicle cabincoordinates.

An alternate, related, method of determining the driver's eye location,useful for either embodiment, will be described further below whichrelaxes even the assumption that the driver sit centered in the fore-aftseat plane. For now, we proceed next to describe how the requiredsideview mirror angular orientation is determined such that the trueblind spot imagery is presented to the driver in the mirror regardlessof driver stature or fore-aft seat position. The explanation is in thecontext of the first variation of the second embodiment, but similarcomputations must be performed for orienting the sideview mirrors in thecase of all variations of either embodiment.

Determination of Correct Mirror Orientation for Either First or SecondEmbodiments

The nominal direction cosines of the blind spot axis are known a 'priorifor a given mirror mount placement and vehicle model. Any variations dueto changes in driver eye height or fore-aft position from nominal can beincluded in a suitable mathematical model in the vehicle microcomputer52 dependent on the location of the driver's eyes. This may be installedas a look-up table of changes in blind spot direction cosines from thenominal ones given the changes in drivers eye location from nominal“x,y” locations in the fore-aft seat plane 82. The look-up table can beused to derive the true blind spot direction cosines relative to thecenter “reference” point of the sideview mirror from the x,y parametersof the driver's eye location.

Let us denote these three true direction cosines to the blind spot bythe vector [p_(b), q_(b), r_(b)]. Again, these direction cosines definea unit vector 70, this time pointing from a vehicle fixed reference ororigin point (typically at or very near the center of the mirror) downthe axis of the conical volume defining the blind spot 30 and toward theblind spot. (The corresponding displacement, or distance, vector betweenthe driver's side sideview mirror 20 and blind spot 30 shown in FIG. 8is simply the linear extension of the unit vector 70 and is identifiedby the same number, 70, in FIG. 8.) Any required small depression angleto account for the fact that a driver usually wishes to see the roadsurface some distance behind a vehicle centered in the mirror isincluded in the unit vector 70.

In the case of the first variation of the second embodiment, it is notnecessary that the driver direction reference point on the LED 40 becoincident with the blind spot direction reference point on the mirror20, although this condition does simplify the computation of therequired mirror alignment somewhat: In the case of an LED, 40 housed inthe sideview mirror assembly, the pivot center of the LED 40 can be mademuch closer to the center and/or azimuth rotation axis of the mirror 20than shown in FIGS. 6 and 7, so the above assumption can be made valid.For more general locations of the LED 40, it is necessary that the abovetwo sets of direction cosines, i.e. the two unit vectors, be measuredwith respect to the same vehicle fixed coordinate system. In the generalcase, it is also important and that any vector displacement between thetwo reference points (mirror reference point and LED reference point)through which these direction cosine vectors pass be accounted for inthe vector mathematics. In many practical implementations of the secondembodiment of the present invention, it may be desirable to place theLED 40 inside the vehicle, well removed from the mirror reference point.Examples of such locations for the second variation of the secondembodiment are shown in FIGS. 9 and 10 described below.

For either embodiment, the microcomputer 52 then computes or, moresimply looks up in a stored look-up table, the required directioncosines associated with the mirror normal vector when the mirror iscorrectly positioned. This mirror normal vector constitutes yet anotherunit vector. Let us denote the mirror normal unit vector 74 (hereincalled the “mirror normal”) by the ordered tuple [p_(m), q_(m), r_(m)].Being a vector normal to a plane, the mirror normal 74 may be translatedfreely anywhere over the mirror surface. In particular, it may be placedat the same common origin used for the driver and blind spot directionvectors.

The required three conditions or constraints that allow the threeunknown quantities p_(m), q_(m), r_(m) to be derived are: (1) that themirror normal 74 must be in the plane of the incident central ray fromthe blind spot (approximately known a 'priori and subsequently refinedin the microcomputer 52 to accommodate the actual location of thedriver's eyes 80) and the reflected central rays 32 heading towards thedriver's eyes (collinear with the LED pointing direction in the firstvariation of the second embodiment); (2) that the mirror normal 74 mustbisect the angle formed between the incident and reflected central rays32, and (3) that the mirror normal 74 has unit length. The first twoconstraints arise from the properties of plane mirrors and guaranteethat the blind spot image will be directed exactly at the driver's eyes,regardless of his or her eye level and fore-aft seat position. The thirdconstraint is a simple property of all unit vectors, namely given twodirection cosines of a unit vector the third is automatically defined.

After [p_(m), q_(m), r_(m)] are solved for, the corresponding mirrorpitch and azimuth Euler angles, Θ_(M) and Φ_(M), respectively, for thecorrect mirror position are computed. The fact that only two, ratherthan three, such angles result is consistent with the fact that rotatinga mirror about its normal axis does not change the direction thatincident rays are reflected. These angle computations are allstraightforward, although nonlinear because of the trigonometricfunctions involved. As the mathematics involved in either the driver'seye location determination or the optimal mirror orientationdetermination are well known to those skilled in optical ray tracing andcomputer analysis of lens and mirror systems, no detailed equations needto be given here.

In some implementations of the first and second preferred embodiments,no equations would actually be solved during sideview mirror alignment.Rather, for all possible observed LED pitch and azimuth gimbal angles,Θ_(L) and Φ_(L), the corresponding required mirror gimbal angles, Θ_(M)and Φ_(M) of the correct mirror position for the particular vehiclewould be derived a 'priori by the mirror manufacturer and stored in alook-up table in ROM associated with the microcomputer 52. Thereafter,the required mirror gimbal angles, Θ_(M) and Φ_(M) for the observed LEDpitch and azimuth gimbal angles, Θ_(L) and Φ_(L), would be simply lookedup in the ROM look-up table by the microcomputer 52 once the pickleswitch 56 is closed by the driver. Practically speaking, this wouldcollapse the two steps of driver's eye location determination and mirrororientation determination into one table operation in both embodiments.However, in other applications, such as controlling air-bag deploymentcharacteristics, explicit determination of the driver's eye location maystill be required.

Next, the mirror 20 would be automatically servoed, first about theazimuth (outer) gimbal 35, and second about the pitch (inner) gimbal 33by pitch and azimuth mirror drive signals generated by the microcomputer52. The above order assumes a certain convention in defining the Eulerangle transformations. A different convention might result in theservoing being conducted first about pitch and then about azimuth. Theresultant final mirror 20 orientation would be identical in either case,although the commanded Θ_(M and Φ) _(M) values would be different.

Regardless of the Euler angle convention adopted, appropriate mirrorgimbal angle encoders or pickoffs 38, 41 are employed so that acontinuous feedback of the actual mirror angular orientation is returnedto the microcomputer 52 during the servo operation. This will insurethat the mirror servo motors 34, 36 are run in the correct directionsand are stopped when correct alignment is obtained. At completion, theblind spot image is reflected directly into the driver's eyes.

A suitable indicator, such as a green LED, may be momentarily energizedto signal to the driver that a condition of proper alignment has beenachieved. Another refinement to the second embodiment would be theincorporation of a panel warning light similar to the “door ajar”warning to indicate a malfunction in the alignment aid.

Adjustment of the Passenger's Sideview Mirror Orientation in BothEmbodiments

Before describing in detail the various variations of the first andsecond embodiments, attention is directed to the adjustment of thepassenger's side sideview mirror along with the adjustment of thedriver's sideview mirror. In the simplest “baseline”, version of thefirst variation of the first embodiment, each mirror assembly 27 isconfigured in the manner of FIGS. 4 and 5. Each mirror assembly 27includes its own LED 40, 40′ pointed at its nominal blind zone, and eachmirror 20 has its own auxiliary mirror 24 to deviate the light beams 42and 42′ into the driver's eyes as he/she manually adjusts the mirrors 20and 20′.

Similarly, in the simplest, “baseline”, version of the first variationof the second embodiment, each mirror assembly 27 would be configured inthe manner of FIGS. 6 and 7 and would have its own LED 40, 40′ that thedriver orients so that he/she sees a maximum light spot intensity ineach sideview mirror 20, 20′.

These baseline versions are also described with respect to FIG. 8. It isassumed that the fore-aft seat plane coordinates are known. The driver'seye location is defined for either mirror 20, 20′ as the intersection ofan extended direction cosine vector (unit vector) from each mirror andthe fore-aft seat plane. These vectors are denoted as 66 and 68 in FIG.8. The microcomputer 52 may be shared with both mirror assemblies andthen simply computes the driver's eye location and mirror alignmentstwice, as the driver signals completion of the manipulation of thecontrol knob for each mirror and then automatically adjusts eachsideview mirror 20, 20′ to the computed alignments via the appropriatemirror servo motors.

In the baseline version of either embodiment, the driver's eye locationis determined for each mirror and used to align that mirrorindependently of the other mirror. This is possible because only onelight source and beam, for example the driver's side sideview mirrorlight beam 42, and the corresponding distance vector 66, is necessaryfor the location of the driver's eyes 80 to be computed. This is becausethe midpoint of the eyes 80 should also lie in the vertical fore-aftseat plane 82 passing through the center of the driver's seat anddirected fore-aft in the vehicle 10 if the driver is properly seatedbehind the steering wheel. The seat plane 82 and mirror subassemblycoordinates with respect to the vehicle 10 are known. The extended unitvector from mirror 20 (or 20′) to the driver's eyes 80 constitutes adistance vector 66 (or 68) in 3-D space. Since the distance vector 66(or 68) can intersect plane 82 in at most one point, one can again makeuse of basic geometry and solve for the location of the driver's eyes 80where the line and plane intersect. This point is the midpoint locationof the driver's eyes 80.

However, it is usually preferred to avoid the expense of incorporating asecond LED 40′ and associated components in the passenger's side,sideview mirror in the first variations of both the first and secondembodiments. Moreover, it may be desirable to simplify the alignmentprocedure to avoid having to involve the driver in adjusting twosideview mirror mounted light beams in the manner described above. Thiscan be advantageously accomplished, because the driver's eye locationcan be determined from the measured pitch and azimuth adjustment of thelight beam direction accomplished by direct adjustment of the lightsource (per the second embodiment) or an adjustable light beam reflectorintersecting a fixed direction light beam from a fixed light source (perthe first embodiment) as described above. The angles of adjustment inpitch and azimuth are measured, and the location of the driver's orpassenger's eyes is determined using triangulation techniques employingthe measured angles and the known Cartesian coordinates of pitch andazimuth axes of adjustment of the adjustable light source or light beamreflector and the known fore-aft seat adjustment plane for therespective driver's or passenger's front seat.

Once the driver's eye location is determined for the first or driver'ssideview mirror in either embodiment, the geometry of the vehicledictates how the second or passenger's side mirror should be aligned.For a range of possible driver's eye locations within the driver'sfore-aft seat plane, corresponding sets of mirror pitch and azimuthangle settings can be is derived to image the vehicle blind spots for agiven vehicle and used to construct a lookup table in memory in themicrocomputer 52. Both mirrors may be adjusted from their current pitchand azimuth angles to the required pitch and azimuth angles using thelookup table settings. The second mirror may be then be automaticallypositioned by mirror pitch and azimuth adjustment signals derived by themicrocomputer 52 and applied to the servo motors.

Referring again to FIG. 8, from the final alignment. of the mirror 20,the left hand mirror normal 74 represented as a tuple [p_(m), q_(m),r_(m)] is derived as described above in regard to the second embodiment.In a like manner, the components of the mirror normal 74 represented asa tuple [p_(m), q_(m), r_(m)] can also be derived in the firstembodiment employing the microcomputer 52 and pickoffs 38, 41. Then,from the stored body of position data identified above, the right handsideview mirror normal 76, represented as a tuple [p_(m), q_(m), r_(m)],may be determined for proper alignment of the mirror 20′ with respect tothe driver's eyes 80 in the fore-aft seat plane 82.

More particularly, first consider the second embodiment of the inventionfor which the simplification manifests itself most directly. There,knowledge of the location of the fixed reference point for mirror 20 in3-D space along with knowledge of the direction cosines corresponding todistance vector 66 from mirror 20 to the driver's eyes 80 allows thelocation of the driver's eyes to be determined in 3-D space as explainedfor the baseline variation earlier. This is because the midpoint of theeyes 80 should also lie in the vertical fore-aft seat plane 82 passingthrough the center of the driver's seat and directed fore-aft in thevehicle 10 if the driver is properly seated behind the steering wheel.In turn, knowledge of the location of point 80 and the also fixedreference point for mirror 20′ allows distance vector 68 from 20′ to 80to be computed. Given distance vector 68, one can readily compute thedirection cosine tuple [p_(d), q_(d), r_(d)]′ of the correspondingdirection vector. Next, since the location 30′ of the right hand blindspot is known a 'priori as a function of driver's eye location so is thedirection cosine tuple [p_(b), q_(b), r_(b)]′ defining the displacementvector 72.

Finally, given the direction cosines of displacement vectors 68 and 72one may solve for the direction cosines of the right hand mirror normal76 and the corresponding Euler pitch and azimuth angles. This last stepuses the same set of equations as employed with the second embodiment.

Servo positioning of the right hand sideview mirror 20′ (using mirrorangle adjustment measuring pickoffs 38′, 41′ and pitch and azimuth servomotors 34′ and 36′ mounted on gimbals 33′ and 35′ in the passenger'ssideview mirror subassembly) can then proceed under control of themicrocomputer 52 with no further driver intervention. This is thesituation assumed in FIG. 7 where the pitch and azimuth drive signalsfor the right hand, or passenger's, sideview mirror servo motors aregenerated by the microcomputer 52 after the left hand, or driver's,exterior mirror adjustment is completed.

For example, the comprehensive version of the first embodiment systemdepicted in FIG. 5 may be employed to eliminate the need for an LED 40′in the passenger's side sideview mirror 20′ and for any driver actionsto align this mirror when the driver's side sideview mirror 20 isaligned. Rather, it is possible to derive the approximately correctpitch and azimuth angle positions of the right sideview mirror 20′ whenthe driver signals completion of the manual adjustment of the leftsideview mirror 20 such that the light beam 40 is seen to themicrocomputer 52.

A Variation of the Derivation of the Driver's Actual Eve LocationApplicable to Either the First or Second Embodiments

FIG. 8 schematically depicts both left and right sideview mirrors 20 and20′ correctly aligned to the driver's eyes 80 to view the blind spots 30and 30′, respectively, in accordance with either of the aboveembodiments. For each mirror 20, 20′, the components of the mirrorsubassembly 25 and mirror assembly 27, such as the mirror housing 22,LED sources 40, gimbals, servo motors, etc., of FIGS. 1-7, are notdepicted in FIG. 8 for simplicity. Only the schematic symbols 20, 20′for the two mirrors along with the appropriate left and right mirrornormals 74 and 76, and the associated distance, or displacement, vectors66, 68, 70, and 72 are depicted. The displacement vectors are simply thelinear extensions of the corresponding unit vectors bearing the sameidentification numbers, as noted earlier.

From FIG. 8, it can be seen that the two distance, or displacement,vectors 66, 68, intersect between the driver's eyes 80. Thisintersection point defines the exact current location of the driver inthe car seat along the fore-aft driver's seat adjustment plane 82, notjust a direction to his/her eyes 80. The two distance vectors 66 and 68represent the straight line extensions of the unit vectors representedby the two direction cosine tuples [p_(d), q_(d), r_(d)] and [p_(d),q_(d), r_(d)] from their known origins (at or very near the mirrorreference points). By definition, at correct mirror alignment, these twodistance vectors 66, 68 must intersect at the midpoint between thedriver's left eye and right eye.

In the context of the first variation of the second embodiment where theLEDs 40, 40′ are adjustable to directly point at the driver, thedistance vector 66 lies along the transmitted light beam 42 emanatingfrom the left mirror center or reference point. The distance vector 68similarly lies along the transmitted light beam 42′ (assuming a LED 40is actually present in the right sideview mirror subassembly) withrespect to the right mirror center or reference point. Refer to FIG. 8for the following discussion. In this variation for determining thedriver's eye location, the right sideview mirror subassembly includes anLED source 40 emitting light beam 42′. The two light beams 42 and 42′are both adjusted by the driver to point at his or her eyes 80 asdescribed above. Then, as also noted above, the point where the twodistance vectors intersect is the location of the driver's eyes, 80.

A similar first variation for determining the driver's eye location isalso possible with the first embodiment since the microcomputer 52 andpickoffs 38, 41 are employed for that embodiment as well. To understandthis, it must be recalled from the above description of the firstembodiment and its baseline version that the position Cartesiancoordinates for the mirror reference points and pitch and azimuth axesof the mirrors 20, 20′ and the associated LED sources 40, 40′, and thefore-aft driver's seat adjustment plane 82 are known a 'priori for thespecific vehicle and stored in memory in microcomputer 52. Hence, bymeasuring the pitch and azimuth alignment of the mirror 20, after thedriver has manually adjusted the mirror to reflect the fixed light beaminto his/her eyes the driver side direction cosines [p_(d), q_(d),r_(d)] can be computed from their known origins (at or very near themirror reference point). Similarly, by measuring the pitch and azimuthalignment of the mirror passenger side mirror 20′, after the driver hasadjusted that mirror to reflect the fixed, light beam into his/her eyesthe passenger side direction cosines [p_(d), q_(d), r_(d)m]′ can becomputed from their known origins (at or very near the passenger mirrorreference point). In turn, the unit vector 66 pointing from the leftsideview mirror to the driver's eyes may be solved for mathematically ascan the unit vector 68 from the passenger side to the driver. From thetwo driver's eye unit vectors 66, 68, the actual location of thedriver's eyes 80 in the fore-aft seat plane 82 may be determined in thisfirst variation of the first embodiment, just as the driver's eyelocation may be determined in the second embodiment as described above.In either embodiment with this variation, both sideview mirrors may besubsequently adjusted under computer control to their optimal positionsto reflect driver's side and passenger side blind spot imagery into thedriver's eyes.

Variations as to the Location of the Light Source(s) of the SecondEmbodiment

In the detailed description and illustration of the first variations ofthe first and second preferred embodiments to this point, the lightsource(s) 40 is positioned within the mirror housing(s) 22 behind themovable mirror subassembly(s) 25, thereby requiring the selectivelytransmissive region 21. The present invention contemplates thepossibility that the light source(s) 40 may be otherwise positioned andsupported fixedly or for movement in pitch and azimuth while performingthe same functions as described above. In this regard, there are anumber of advantages of removing the light source(s) to location(s)within the vehicle cabin, wherein it or they may be more convenientlyused to locate the passenger's eyes in the passenger's fore-aft seatplane.

FIG. 9 illustrates one or two light sources 40, 40′ or 40″ and theassociated light beam direction pitch and azimuth angle adjustment andpickoff components mounted at convenient location(s) inside the vehicle10. The light sources 40, 40′ or 40″, for example, can be mounted atsome distance(s) outside the fore-aft seat plane 82 at sites that aredefined a priori, so that the light beam(s) 42, 42′ or 42″ direction(s)are not coplanar with the fore-aft seat plane 82 as in FIG. 8. Lightsource 40″ can be mounted, for example, in association with the interiorrearview mirror for transmitting a light beam through a semi-transparentregion of the movable rearview mirror in the manner of the system ofFIG. 7. As described above in reference to FIGS. 7 and 8, the adjustmentof the light beam direction(s) to be seen by the driver 12 can thereforebe used to derive the left and right sideview mirror pitch and azimuthdrive signals.

Turning to FIG. 10, it depicts a system in accordance with this aspectof the invention wherein one of the light source 40, 40′ or 40″ of FIG.9 is shown in relation to driver 12 and a driver's side, sideview mirrorassembly 27. For convenience, the driver 12 is shown facing forwardwhereas the driver 12 would actually face into the drawing sheet planetoward light beam 42 and the reflected blind spot light ray 32. Thedriver 12 manipulates the joystick control 54 to see the light beam 42,the light beam pitch and azimuth angles of adjustment are measured, andthe driver's eye location is determined in the manner described abovewith respect to FIGS. 7-9. The driver's eve location in fore-aft seatplane 82 is then employed to determine the pitch and azimuth drivesignals for adjusting the pitch and azimuth settings of the sideviewmirrors as described above in reference to FIGS. 7-9.

In the system of FIG. 10, it will be understood that the light source 40can also be located in relation to the vehicle interior rearview mirror.In this case, the LED 40 and its associated pitch and azimuth adjustmentdrive motors 44 and 46 and pickoffs 48 and 51 may be located in themirror housing behind the rearview mirror reflective surface to transmitthe light beam 42 through a selectively transmissive region in themanner described above or on the interior rearview mirror housing.

In this variation, the adjustment of the interior rearview mirror by thedriver has no effect on the direction of the light beam 42 of FIG. 10.The direction of the light beam 42 is independently adjusted by thedriver 12 as described above, and the sideview mirrors are also adjustedin response as described above with respect to FIG. 7. However, it iscontemplated in this variation that the spontaneous adjustment of theinterior rearview mirror may be sensed by the microcomputer 52 and usedto prompt the driver to commence the determination of the driver's eyelocation and adjustment of the sideview mirrors. Therefore, the lightsource 40 is illuminated whenever the rearview mirror is adjusted, andthe driver is prompted to complete the adjustment until the light beamis seen and to signal the microcomputer that it has been seen.

A Second Variation of the First Embodiment Employing Adjustment of theVehicle Interior Rearview Mirror

In a still further variation of the system of the first embodimentdepicted in FIG. 5, it is contemplated that the manual adjustment of theinterior rearview mirror may be itself employed to derive the driver'seye location and to derive sideview mirror adjustment signals. In thisvariation, the microcomputer-based mirror adjustment and driver's eyelocation system of FIG. 5 does not employ the light source pitch andazimuth servo motors 44, 46 and joystick control 54. The light source 40is located in relation to the interior vehicle rearview mirror so thatthe adjustment of the mirror reflects the light beam direction 42: Therearview mirror is mounted to a mount allowing it to be manuallyadjusted in pitch and azimuth, and the pitch and azimuth pickoffs 48 and51 are provided to measure its adjustment. The rearview mirror isadjusted to pitch and azimuth angles that allow the light beam 42 tointersect the driver's eyes 80 in the fore-aft seat plane 82. Thedriver's eye location are then determined from the measured, adjustedpitch and azimuth angles. Sideview mirror pitch and azimuth drivesignals are then derived and employed to set the pitch and azimuth ofthe sideview mirror(s) in the manner described above with respect toFIG. 10, for example. This system may also be used to determine thepassenger's eye location in the passenger's fore-aft seat plane.

One example of such a further variation of the first embodiment isillustrated in FIGS. 11-15. In this variation, a light beam 142 is fixedwith respect to the interior rearview mirror 120, and the direction of areflected light beam 142′ is adjusted in pitch and azimuth by theadjustment of the interior rearview mirror 120. This variationincorporates a doublet auxiliary mirror 124 and the principles ofoperation of portions of both the first and second embodiments. Thisvariation enjoys the advantage of being completely located inside thepassenger compartment of the vehicle 10 and being likely to be used bythe driver 12 whenever the interior rearview mirror 120 is adjusted.Pitch and azimuth angle pickoffs 138 and 141 are coupled to the rearviewmirror gimbal mechanism 104 in order to provide pitch and azimuthsignals that are employed to determine the driver's eye location and todetermine the sideview mirror adjustment signals. Through opticalrelationships illustrated in these figures, the adjustment of theinterior rearview mirror 120 to make the reflected light beam 142′visible to the driver 12 also results in proper adjustment of therearview mirror 120 to reflect an image of the rearward scene 130visible through the vehicle rear window 110.

In FIGS. 11 and 12, the doublet auxiliary mirror 124 comprises amicro-miniaturized azimuth reflective mirror surface 124 a and a pitchreflective mirror surface 124 b that are mounted at right angles to oneanother. In FIG. 11, the doublet auxiliary mirror 124 is mounteddirectly behind the rearview mirror reflective surface 126 in fixedrelation to a selectively transmissive region 121 of the type describedabove. In FIG. 12, the doublet auxiliary mirror 124 is mounted directlyto the mirror edge or frame to be moved with rearview mirror 120.

The rearview mirror 120 is mounted for manual or remote motorizedadjustment about the pitch and azimuth mirror axes 139 and 137 employinga typical rearview mirror gimbal mechanism 104. The rearview mirrorgimbal mechanism 104 includes a rearview mirror azimuth gimbal 135defining the azimuth mirror axis 139 and a rearview mirror pitch gimbal133 defining the pitch mirror axis 137.

In FIGS. 13 and 14, the adjustment in azimuth of the rearview mirror120, so that light rays 132 of the image of the rearward scene 130passing through rear window 110 are optimally viewed by the driver 12located in the fore-aft seat plane 82, is illustrated. The light beam142 is emitted in a fixed light beam direction either directly from alight source 140 located forward of the rearview mirror 120 orindirectly off a fixed mirror located forward of the rearview mirror120. In these illustrations, it is assumed that the rearview mirror 120is mounted by rearview mirror gimbal mechanism 104 in the vehiclefore-aft centerline, as is typically the case. If this is not the case,the directions of the light beam 142 and the normal pitch and azimuthangles described below can be adjusted to compensate for the location ofthe mirror mount 102 and/or mirror gimbal mechanism 104.

In FIG. 13, the pitch mirror surface 124 b is not shown for convenienceof illustration. The fixed direction of light beam 142 forward ofrearview mirror 120 is angled so that it reflects off the azimuthsurface 124 a near its root with the reflective surface 126 in allazimuth positions of the rearview mirror 120. In reference to FIGS. 11and 12, the reflected light beam 142′ is either directed alongside therearview mirror 120 or through the selectively transmissive region 121.

As shown in FIGS. 13 and 14, the azimuth surface 124 a is mounted sothat it is not necessarily at 90° to the rearview mirror surface 126.The specification of the precise mounting angle of azimuth surface 124 awith respect to the plane of reflective mirror surface 126 depends on anumber of vehicle specific factors and the chosen fixed angle of thelight beam 142 striking it.

The reflected light beam 142 is directed rearward approximately inalignment with the vehicle fore-aft centerline axis and vertical planeand in coincidence with the rearward scene light rays 132 when thereflective mirror surface 126,is at the nominal 0° azimuth adjustment.Consequently, the nominal 0° azimuth adjustment is defined as theperpendicular, in azimuth, orientation of the reflective mirror surface126 to the vehicle fore-aft seat plane 82. Thus, the reflected lightbeam 142′ is directed approximately through the center of the rearwindow 110 as long as the rearview mirror 120 is at 0° azimuth. In thenominal rearview mirror azimuth position, the driver 12 can neither seethe reflected light beam 142′ nor optimally see the rearward scene 130.The rear image light rays 132 from the rearward scene 130 are reflectedstraight back in this rearview mirror azimuth position.

Turning to FIG. 14, the rearview mirror 120 is shown adjusted in azimuthso that the reflected light beam 142′ is directed into the driver's eyes80. The azimuth adjustment is directly proportional to the fore-aftlocation of the driver's eyes in the fore-aft seat plane 82. Thisazimuth adjustment of rearview mirror 120 also reflects the reflectedrear image light rays 132′ into the driver's eyes in substantialcoincidence with the reflected light beam 142′.

The rearview mirror 120 also must be adjusted in pitch to compensate forthe driver's eye height of the driver 12 in the fore-aft seat plane 82,so that the driver 12 can see the reflected light beam 142′ andoptimally view the reflected image of the rearward scene 130. Thelocations of the driver 12 (assumed to be in the fore-aft seat plane 82)and the driver's eyes 80 in a horizontal, up-down plane 84 areillustrated in FIG. 15. The pitch surface 124 b is normally at 90° tothe azimuth surface 124 a.

Typically, the rearview mirror 120 is located above the driver's eyes80, assuming that the driver 12 locates the seat height to a comfortableposition where his/her head does not contact the vehicle roof. When therearview mirror reflective surface 126 is perfectly perpendicular or atsome other preset pitch angle, a nominal rearview mirror pitch,designated 0°, is defined. This nominal pitch typically would not allowthe driver 12 to see optimally through the center of the rear window110. In this nominal pitch position, the light beam 142 is not reflectedfrom pitch surface 124 b.

In the typical range of fore-aft and up-down locations of the driver'seyes 80, the rearview mirror 120 is tilted in pitch from the nominalpitch angle, and the light beam 142 is also reflected from the pitchsurface 124 b. One such pitch position and the driver's eyes locationare depicted in FIG. 15. In the illustrated pitch adjustment of therearview mirror 120, the reflected rear image light rays 132′ are alsodirected to the driver's eyes 80. The deviation in pitch angle from thenominal 0° angle by pitch gimbal angle Θ_(L), that allows the driver 12to see the reflected light beam 142′ and the image of the rearward scene130 is measured by the pitch angle pickoff 138 (FIGS. 11 and 12).

This variation of the invention may be implemented to determine thedriver's eye location and to adjust the vehicle sideview mirrorsemploying the other components and methodology of FIG. 10. In this case,the LED pitch and azimuth servo motors 44 and 46 and associated motordrive signal generating functions initiated by use of the joystickcontrol are eliminated. The rearview mirror pitch and azimuth anglepickoffs 138 and 141 are coupled to the microcomputer 52. The driver isprompted by any of the known prompts to adjust the interior rearviewmirror and expect the adjustment of the sideview mirrors upon startingthe engine, adjusting the seat position, spontaneously adjusting theinterior rearview or exterior sideview mirrors, etc. Assuming that boththe pitch and azimuth adjustments are completed, the driver. 12initiates the determination of his/her eye location and/or theadjustment of the vehicle sideview mirrors by providing a signal to themicrocomputer 52 in the manner described above in reference to FIGS. 7and 10 indicating that he/she can see the reflected light beam 142′.

When the driver signals that he/she can see the reflected light beam142, the azimuth gimbal angle Φ_(L) from the normalized or 0° azimuthangle shown in FIG. 13 is measured by the azimuth angle pickoff 141,thereby developing a measured azimuth angle of adjustment signal that isapplied to the microcomputer 52, as in the systems of FIGS. 7 and 10.The microcomputer 52 determines the fore-aft location of the driver'seyes 80 in the fore-aft, vertical seat plane 82 from the measuredazimuth angle of adjustment signal and from the Cartesian coordinates ofthe fore-aft seat plane 82 and the rearview mirror 120 about therearview mirror pitch and azimuth axes 139 and 137 as described above inregard to FIG. 7.

Similarly, the driver's vertical eye location, i.e., the horizontalplane 84 coordinates, is derived by the microcomputer 52 from thefore-aft location of the driver's eyes 80 in the fore-aft, vertical seatplane 82 and the measured pitch angle of adjustment signal.

As described above, the driver's eye location data may be used for avariety of purposes including the adjustment of the vehicle sideviewmirrors to reflect the image of the vehicle blind spots. Continuing withthe adjustment of the sideview mirrors, the microcomputer 52 derives anazimuth sideview mirror positioning signal for either or both of thedriver's side and passenger's side sideview mirrors from the measuredazimuth angle of adjustment of the reflected light beam 142 and from theCartesian coordinates of the fore-aft seat plane 82, the respectivevehicle side blind spot for each such sideview mirror, and therespective sideview mirror pitch and azimuth axes 39 and 37 as describedabove in regard to FIGS. 7 and 10. Then, the respective azimuth sideviewmirror positioning signal is employed to align the respective sideviewmirror to reflect the image of the respective vehicle side blind spotinto the driver's eyes. In a similar fashion, the respective pitchsideview mirror positioning signals are derived and employed to adjustthe pitch of the respective sideview mirrors.

Returning to FIG. 15, it also depicts one further location for a lightsource 140 in association with a vehicle headliner assembly 190typically including a set of interior lamps and located above andfrequently rearwardly of the rearview mirror mount 102. The light source140 emits the light beam 142 downward and possibly forward to a fixedreflector or mirror 94 that reflects the light beam 142 into the fixedlight beam path illustrated in FIGS. 13 and 14, for example.

Locating the Passenger's Eye Position

The above-described embodiments of FIGS. 7-15 may be modified as shownin FIG. 16 to derive the eye location of a passenger 14 in the vehiclefront passenger's seat 88 in the passenger's seat 88. Moreover, the dataidentifying the location of the driver's eyes 80 and the passenger'seyes 80′ may be employed to vary the characteristics of airbagdeployment of the vehicle airbag(s) for each vehicle seat. FIG. 16comprehensively illustrates both of these variations of the presentinvention for airbags located to protect occupants of the front seats.

In order to initiate the operations to derive the location of thedriver's eyes 80 or the passenger's eyes 80′, it is necessary to providean identification signal through a button switch or the like to themicrocomputer 52′ identifying which seat location is being sought. Thelocation may be effected employing components and functions described inrespect to the embodiments of FIGS. 7-15 in each of the above-describedsystems. In regard to location of a passenger's eyes in the passenger'sseat 88, the direction of the light beam 42 may be adjusted in pitch andazimuth by the driver or the passenger 14, if the passenger is capableof doing so, until it is seen by the passenger 14. The light beam pitchand azimuth adjustments may be effected by movement of the light sourceitself or a reflector located in the light beam path, e.g. a doubletauxiliary mirror or the like by adjustment of the joystick control 54.The system of FIGS. 11-15 can be used if it is provided with asufficient pitch and azimuth adjustment range to be directed upon smallstature passengers.

Then, the pitch and azimuth angles of adjustment are measured from thepitch and azimuth pickoffs coupled to the pitch and azimuth adjustmentaxes of the adjustable light source or light beam reflector. Thelocation of the passenger's eyes 80′ is derived by the microcomputer 52′in the manner described above, employing the known Cartesian coordinatesof the adjustable light source or light beam reflector and the fore-aftpassenger seat plane 86.

Control of Airbag Deployment Characteristics

In a further application of the present invention, the derived locationsof the driver's eyes, the passenger's eyes are used to determine thedistance between the airbag and the same, and the distance is used tocontrol the characteristics of deployment of the airbag. The controlledcharacteristics of deployment of the airbag to account for thedetermined distance comprise one or more of the airbag inflation force,the rate of inflation and the inflation duration.

In regard to control of the driver's side airbags 96 and 97, thedriver's eye location is derived in any of the manners described above.The microcomputer 52′ is modified to derive driver's side airbaginflation force, rate and duration control signals using an appropriatelook-up table, for example, tailored to the particular vehicle seatingconfiguration, airbag locations and types and other appropriate factors.The airbag inflation force, rate, and duration control signals areapplied to the airbag deployment force and duration control system 108which in turn controls the deployment of the airbags 96, 97 accordingly.

Similarly, once the location of the passenger's eyes 80′ is determined,the microcomputer 52 calculates an adjustment in the inflation force,rate of inflation, and inflation duration of the passenger's sideairbags 98 and 99. The airbag force and duration adjustment signal isapplied to the airbag deployment system, particularly to the airbagdeployment force and duration control system 108 which in turn controlsthe deployment characteristics of the airbags 98, 99.

Many of the considerations to be taken into account and a system blockdiagram for making the airbag deployment decision and controlling theinflation force and duration or rate of inflation of single stage ormulti-stage airbags are set forth in the above-referenced articleentitled “Restraint system electronics”, incorporated herein byreference. After the driver or passenger is located in accordance withthe present invention, the distance between the same and the respectiveairbag(s) may be determined, and the airbag deployment controlled in themanner described therein. In this article, a variety of sensors aredescribed for attempting to determine the position of the driver,passenger(s) and other vehicle characteristics, e.g. vehicle speed andthe like, that provide signals that are proposed to be combined tocontrol the deployment of airbag(s). In this regard, the determinationof the driver's eye location, the passenger's eye location of thepresent invention may be employed in conjunction with the signalsderived from these sensors in order to more accurately confirm theposition of each.

Final Comments

As noted at the outset, FIG. 17 is a schematic illustration of a housing200 for a light beams 202 and 204 of the light beam pair that is usableFIGS. 3-16, and FIG. 18 illustrates the relationship of the light beampair 202 and 204 to the eyes of an occupant of a vehicle. The lightbream sources 40, 40′, 40″, 140FIGS. 3-16 can be replaced by the lightbeam source or housing 200FIGS. 1-8, whereby the mechanisms foradjusting the light beam pair direction 218, measuring the light beampair direction 218 and determining the location of the occupant's eyesor other target are accomplished by the associated components depictedin FIGS. 3-16 and described above.

In the above description and the following claims, no requirements willbe made on the microcomputer as to whether it is a general purpose orspecial purpose unit and whether it is integrated in the mirror hardwareor not. The microcomputer may be a general purpose vehiclemicrocomputer, used for other functions such as computing gas mileagecomputation or climate control, or a special purpose processor orcomputer, strictly dedicated to the mirror alignment functions describedin this application. The general adjectives “vehicle”, “on-board” and/or“integrated” covers all locations and types of microprocessors ormicrocomputers used by the mirror blind spot reduction technologydescribed herein. If an integrated microcomputer is employed in eightthe first or second embodiments, it may be located in one or both of themirror housings and included by the mirror manufacturer as part of thedelivered unit.

All patents and other publications identified above are incorporatedherein by reference.

While the present invention has been illustrated and described withparticularity in terms of preferred embodiments, it should be understoodthat no limitation of the scope of the inventtion is intented thereby.The scope of the invention is defined only by the claims appendedhereto. It should also be understood that variations of the particularembodiments described herein incorporation the principles of the presentinvention will occur to those of ordinary skill in the art and yet bywithin the scope of the appended claims.

What is claimed is:
 1. A method of determining the eye location of anoccupant of a vehicle seated in a seat position along a verticalfore-aft seat adjustment plane of the vehicle having reference,predetermined planar Cartesian coordinates comprising the steps of:emitting a light beam pair comprising a right eye light beam and a lefteye light beam in a light beam pair direction from a vehicle lightsource position; adjusting the light beam pair direction in relation toa defined reference light beam direction about light beam adjustmentaxes having predetermined light beam adjustment Cartesian coordinateslocated outside the fore-aft seat plane until the light beam pairintersects the vertical fore-aft seat adjustment plane at an angle ofadjustment so that a predetermined intensity of the right eye light beamis seen by the right eye of the occupant and a predetermined intensityof the left eye light beam is seen by the left eye of the occupant;measuring the angle of adjustment of the light beam pair and providing ameasured angle of adjustment; and deriving the eye location of theoccupant within the fore-aft seat plane from the measured angle ofadjustment of the light beam pair and from the predetermined Cartesiancoordinates of the fore-aft seat plane and the light beam adjustmentaxes.
 2. The method of claim 1, wherein the adjusting step comprisesadjusting the light beam pair until the predetermined intensity of theright eye light beam seen by the right eye of the occupant and thepredetermined intensity of the left eye light beam seen by the left eyeof the occupant are substantially equal.
 3. The method of claim 1,wherein the emitting step comprises emitting the right eye light beam ofa first color and the left eye light beam of a second color differentfrom the first color from the vehicle light source position.
 4. Themethod of claim 3, wherein the emitting step comprises emitting theright eye light beam in a right eye light beam direction diverging fromthe light beam pair direction and the left eye light beam in a left eyelight beam direction diverging from the light beam pair direction,whereby the right and left eye light beams can be seen by the respectiveright and left eyes when the light beam pair direction is adjusted. 5.The method of claim 4, wherein the emitting step comprises emitting theright eye light beam and the left eye light beam from a common housingat the vehicle light source position.
 6. The method of claim 1, whereinthe emitting step comprises emitting the right eye light beam in a righteye light beam direction diverging from the light beam pair directionand the left eye light beam in a left eye light beam direction divergingfrom the light beam pair direction, whereby the right and left eye lightbeams can be seen by the respective right and left eyes when the lightbeam pair direction is adjusted.
 7. The method of claim 6, wherein theemitting step comprises emitting the right eye light beam and the lefteye light beam from a common housing at the vehicle light sourceposition.
 8. The method of claim 1, wherein the emitting step comprisesemitting the right eye light beam and the left eye light beam from acommon housing at the vehicle light source position.
 9. Apparatus fordetermining the location of an occupant of a vehicle seated in a seatposition along a vertical fore-aft seat plane of the vehicle havingreference, predetermined planar Cartesian coordinates comprising: meansfor emitting a light beam pair comprising a right eye light beam and aleft eye light beam in a light beam pair direction from a vehicle lightsource location located outside the vertical fore-aft seat adjustmentplane; means for adjusting the light beam pair direction in relation toa defined reference light beam direction about light beam adjustmentaxes having predetermined light beam adjustment Cartesian coordinatesuntil the light beam pair intersects the vertical fore-aft seatadjustment plane at an angle of adjustment so that a predeterminedintensity of the right eye light beam is seen by the right eye of theoccupant and a predetermined intensity of the left eye light beam isseen by the left eye of the occupant; means for measuring the angle ofadjustment of the light beam pair and providing a measured angle ofadjustment; and means for deriving the location of the occupant withinthe fore-aft seat plane from the measured angle of adjustment of thelight beam pair and from the predetermined Cartesian coordinates of thefore-aft seat plane and the light beam adjustment axes.
 10. Theapparatus of claim 9, wherein the adjusting means comprises means foradjusting the light beam pair until the predetermined intensity of theright eye light beam seen by the right eye of the occupant and thepredetermined intensity of the left eye light beam seen by the left eyeof the occupant are substantially equal.
 11. The apparatus of claim 9,wherein the emitting means comprises means for emitting the right eyelight beam of a first color and the left eye light beam of a secondcolor different from the first color from the vehicle light sourceposition.
 12. The apparatus of claim 11, wherein the emitting meanscomprises means for emitting the right eye light beam in a right eyelight beam direction diverging from the light beam pair direction andthe left eye light beam in a left eye light beam direction divergingfrom the light beam pair direction, whereby the right and left eye lightbeams can be seen by the respective right and left eyes when the lightbeam pair direction is adjusted.
 13. The apparatus of claim 12, whereinthe emitting means comprises means for emitting the right eye light beamand the left eye light beam from a common housing at the vehicle lightsource position.
 14. The apparatus of claim 9, wherein the emittingmeans comprises means for emitting the right eye light beam in a righteye light beam direction diverging from the light beam pair directionand the left eye light beam in a left eye light beam direction divergingfrom the light beam pair direction, whereby the right and left eye lightbeams can be seen by the respective right and left eyes when the lightbeam pair direction is adjusted.
 15. The apparatus of claim 14, whereinthe emitting means comprises means for emitting the right eye light beamand the left eye light beam from a common housing at the vehicle lightsource position.
 16. The apparatus of claim 9, wherein the emittingmeans comprises means for emitting the right eye light beam and the leftlight beam from a common housing at the vehicle light source position.